- David Semitekol
- Chicago, IL
- United States

This conversation is closed.

## Where do you use math in your profession?

One of the most difficult challenges that math teachers face today is motivating their students. This becomes more difficult when faced with the all famous question: "What am I going to use this for?"

Help me with some real world examples of modern day math. Please let me know your profession and what type of math you use to share with our students.

---------

Thank you everyone so much for the contributions! They are great and I wasn't expecting such a turn out. My goal is to gain enough examples and to use them at the start of each lecture. I'm hoping that these examples in the beginning of class will spark the student's interest for the reaming of the lecture and to show that that we really do use math.

There is a difference between having to learn something and wanting to learn something. When we have to learn it we just try to get through it. When we want to learn it, this is when we make breakthroughs. Stimulate the interest in students so that they want to learn math and we increase our probability in someone discovering the next breakthrough.

## Erik Hooymans

At almost every lecture i get a remark that i have finally sparked someone's interested in math !

I think to get someone interested you need to show them that math is in their daily lives and not only in a distant job they maybe once will get.

Hope this helps !

## Michael Hennigan

## O'Neil Poree

Quote the old saw about "the unreasonable efficiency of mathematics in explaining the physical universe'.

## Rikki Ansell

## nagib shagour

What Equals 100%?

What does it mean to give MORE than 100%?

Ever wonder about those people who say they are giving more than 100%?

We have all been in situations where someone wants you to

GIVE OVER 100%.

How about ACHIEVING 101%?

What equals 100% in life?

Here's a little mathematical formula that might help answer these questions:

If:

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Is represented as:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26.

If:

H-A-R-D-W-O-R- K

8+1+18+4+23+15+18+11 = 98%

And:

K-N-O-W-L-E-D-G-E

11+14+15+23+12+5+4+7+5 = 96%

But:

A-T-T-I-T-U-D-E

1+20+20+9+20+21+4+5 = 100%

THEN, look how far the love of God will take you:

L-O-V-E-O-F-G-O-D

12+15+22+5+15+6+7+15+4 = 101%

Therefore, one can conclude with mathematical certainty that:

While Hard Work and Knowledge will get you close, and Attitude will

get you there, It's the Love of God that will. It will put you over the top!

## Krisztián Pintér

2+21+12+12+19+8+9+20 = 103

## nagib shagour

I guess everyone speaks of what he is made off huh ............ ;-)

I hope I did not hurt your feelings Kris.

I only meant to stretch your lips sideways ..... to make a laugh ..... ;-)

## O'Neil Poree

## Pontus Westermark

With God, we can calculate 7+15+4 = 26%, Christ gives us 77, so... Christ > God, that's interesting. Jesus comes in at 74 and completes God to 100%. Similar to Attitude.

Unfortunately, if we add upp rape, hate and murder, we get something like 159, so a much more powerful force of the universe than God.

We can also see that with the hindu deity Adi Parashakti, we get 118, no love required, but he beats God straight out of the box. All we have to aknowledge is that he's proven by math to exist since he adds up to over 100%, and we know numbers like that just don't exist.

Numbers obviously never lie, this night, I changed my faith. The deity "Xxyzixxer Tsuxyvorz Kruxozyxuvurrz" appeared to me in a dream, spilling the truth about the world and mankind. I obviously at first thought "oh my, this must be the work of the devil, the christian god have been conclusively proven over and over by poking wholes at small sections of works of science", but I did the calculation and could you believe it? 651!

I mean, 651!!!!!!!! That's 550 MORE than any love of god can give you!!! That's over six times love of god, not to speak how many God-gods you'd need to even come close! 651/26 gives you some kind of number I'm not even sure my newfound deity approves of!

PRAISE Xxyzixxer Tsuxyvorz Kruxozyxuvurrz!!!!!!

## Comment deleted

## Franciz Desouza

## W T

Will share with some spiritual friends that did not grow up on a farm.

Nice play-on-words.

Mary

## nagib shagour

numbers 14 + 4 + 3 + 5

please clarify

## W T

I have enjoyed all your entries. Very uplifting, and revealing....my kids

especially my daughter, who has a love/hate relationship with Math,

has been enjoying your great lessons.

Thank you Nagib, and sorry, I just typed too fast.

Be Well

## nagib shagour

I am so delighted your kids liked it.

## sanghun lee

## Jonathan Ross

## Rikki Ansell

## nagib shagour

There is sooooo much beauty hidden in the math of our world.

here are a few cute examples that I recently received.

Hope you enjoy them:

Beauty of Maths!

1 x 8 + 1 = 9

12 x 8 + 2 = 98

123 x 8 + 3 = 987

1234 x 8 + 4 = 9876

12345 x 8 + 5 = 98765

123456 x 8 + 6 = 987654

1234567 x 8 + 7 = 9876543

12345678 x 8 + 8 = 98765432

123456789 x 8 + 9 = 987654321

0 x 9 + 1 = 1

1 x 9 + 2 = 11

12 x 9 + 3 = 111

123 x 9 + 4 = 1111

1234 x 9 + 5 = 11111

12345 x 9 + 6 = 111111

123456 x 9 + 7 = 1111111

1234567 x 9 + 8 = 11111111

12345678 x 9 + 9 = 111111111

123456789 x 9 +10= 1111111111

9 x 9 + 7 = 88

98 x 9 + 6 = 888

987 x 9 + 5 = 8888

9876 x 9 + 4 = 88888

98765 x 9 + 3 = 888888

987654 x 9 + 2 = 8888888

9876543 x 9 + 1 = 88888888

98765432 x 9 + 0 = 888888888

Brilliant, isn't it?

And look! at this symmetry:

1 x 1 = 1

11 x 11 = 121

111 x 111 = 12321

1111 x 1111 = 1234321

11111 x 11111 = 123454321

111111 x 111111 = 12345654321

1111111 x 1111111 = 1234567654321

11111111 x 11111111 = 123456787654321

111111111 x 111111111=12345678987654321

Now, take a look at this...

101%

From a strictly mathematical viewpoint:

## W T

## Jonathan Ross

## nagib shagour

Your kind words are a strong motivation

for sharing and interaction.

## Rikki Ansell

As an artist, math also helps me figure out how many sheets of aluminum I need for that sculpture, how many pounds of glass beads I need for that design, and how much all that will cost me. I use math to calculate my time and materials so I can calculate how much a piece must sell for just to break even. Beauty and wonder help me figure out how much the piece will sell for above the break even!

As a photographer, math determines how I frame my photographs, how much I zoom in, how fast my shutter speed must be to capture that frog in mid-leap. It also helps me calculate how much it costs to produce a print in various sizes and materials, how much it costs to frame it, and how much it has to sell for.

Math helps me convert massive numbers like one billion into something I can visualize - like $10,000,000 which is 500 new $20,000 cars. I can SEE 500 cars in any dealer's lot, so math helps me make sense of one billion pennies, and understanding one billion pennies makes understanding 7 billion people on Earth easier. If your students are younger and find $20,000 incomprehensible, math let me calculate how many blades of grass were in one inch of my yard, which let me figure out how much yard it would take to hold 7 billion blades of grass, which is about the area covered by the city of Miami, Fl. or 17,361 football fields.

## Letitia Falk

I was looking at chemicals that made lavender plant roots grow so I knew that for every chemical I added I had to add the same amount of each one and that I had to repeat another plant grown without any chemical in case the conditions (light, nutrients, temperature...) affected how the roots grew instead of the chemical.

So I got all of my data and one of the chemicals made the roots grow more on all of the plants it was tested on, but how could I know that they grew different ENOUGH from the control that this chemical might be worthwhile to use? After all, even plants treated the same way sometimes grew a lot and sometimes only grew a little. Maybe the plants had a lot of variation in root length and this trend was just a fluke? Or a result of growing the plants in a lab instead of outside?

I needed statistics! Statistics take into account the natural amount of variation in samples and tell you if a trend is "significant" or not. I had to try to teach myself all of the formulas I needed for my research so by the time I DID take statistics the next year, I was VERY grateful for the class :)

Statistics is what lets me know that the results of my experiments are actually MEANINGFUL, and because there are consistent amounts of variation allowed (5% usually). Scientists from around the world use the same guidelines and can therefore trust each others results.

Math allows scientists to be objective and to share data that is meaningful according to agreed upon standards. Without it we would see "what we want to see" and would have trouble communicating with one another.

## Fritzie -

Another place mathematics comes into play is less obvious but I think more profound. Mathematics is a model for rigor in drawing conclusions from what one knows or can assume to be true. It is the opposite of "hand waving." The most important influence on my life of my mathematics training is rigor of thought. This has served me in every setting in which I have sought to understand other people's arguments or to define my own.

Mathematics is peculiarly challenging for many people, often providing a unique experience of struggle and breakthrough. The practice and experience of struggle and breakthrough is an invaluable skill for taking on challenging work with confidence later in life- understanding how long something might take, how being stuck feels, and how to break through.

These are some of the ways a strong mathematics background has enabled me to undertake projects and problems which may on their face be unrelated to mathematics.

## Franciz Desouza

1 x 8 + 1 = 9 ,12 x 8 + 2 = 98, 123 x 8 + 3 = 987 ,1234 x 8 + 4 = 9876 ,12345 x 8 + 5 = 98765, 123456 x 8 + 6 = 987654

1234567 x 8 + 7 = 9876543, 12345678 x 8 + 8 = 98765432 ,123456789 x 8 + 9 = 987654321

1.Statistics is mostly used in daily life activities

And most basic is to manage personal finances

+=-,

future value of things to buy,

Present Value

Debit Credit entries , End of day balance

And this goes on infinitely

Ps: I find using Abacus easy for all calculations

## nagib shagour

like the grains of sand on a beach.

Is it the person who puts or arranges them in these beautiful orders that

creates these patterns, or is he/she discovering messages setup by a

higher intelligence creator?

I guess every one is to make his own decision.

I have no clue myself.

## Russell Riendeau

Great question.

As a executive search professional, I disguise math with charts, graphs and drawings to show certain values related to hiring trends and talent management.

For example, my data shows the average job tenure and compares that rate to how companies create incentive programs to stay at the company for longer.

I show data around topics of sales training recvd by the average sales professional. I graph how job changes in a person's career can predict their ability to perform effectively. I chart personal income over a 10 year period to demonstrate if a person is securing the right edcuation and experience to add value to the marketplace.

Any time I can turn what appears to be "my opinion" into a equation, a chart, a graph, etc. , it gives the client a true perspective of the information and allows them to accept as fact easier and then act on the data.

Russ

## scott ohlrich

But, what I found to be most advantageous was to be able to estimate well. It is a skill that most people seem to posess but are not often comfortable using. In the "real world", it appears to me, being accurate to 85 or 90% is good enough. In my work I estimated a lot of the time (emergent operations aren't always conducive to detailed analysis!). For example: How much of this structure is involved in fire and will it stay standing long enough for our crew to extinguish this fire? OR Do I have enough hose to reach from the engine in the street-through the front door-up the stairs-and into the rear bedroom where this fire is?

Good estimating appears, to me, to be a matter of not just paying attention to the details but paying attention to everything, including the details. There is certainly a mathmatical basis to estimating and with practice estimating is a very practical skill to be used across most professions.

## Christophe Cop

Probability theory can be applied in almost any field of research...

I used it for forecasting, predictive modeling and self-adapting decision trees.

Where-ever you have measurements or data... it is applicable.

check this talk:

http://www.ted.com/talks/lang/en/arthur_benjamin_s_formula_for_changing_math_education.html

## Roger Gay

## Jonathan Ross

Another one that is used a lot in photography is the angle of reflectance The incident ray, the reflected ray and the normal to the reflection surface at the point of the incidence lie in the same plane. These are both basic physics but it shows how we use such advanced concepts without even being smart enough to realize it : ) They are ll around us.

## Edward Webber

Now, I am one of those gifted people who was doing algebra prior to preschool, and I can say with surety, I wasted my talent with web development, as the math isn't exactly difficult for this career, though you would be surprised (or maybe not..) how many people still can't do it

Most of my day to day math is simple addition/subtraction for pixel calculations, with simple division for columns. I consider this automatic stuff, but I can imagine it isn't to an average kid in school.

For the server side it really becomes critical. For those who don't know much about the web, this may be of interest to you. I'll use TED.com as an example (all estimates, by the way)..

- Each page view (html code) in this discussion forum is roughly 53.5 kilobytes.

- If you include images, this adds roughly 260K extra to the initial page view (images get cached on the browser after the first hit, so this extra gets removed for repeat visitors)

- I'll guess TED gets roughly 80 million page views per month, 8 million of which are unique visitors.

- The web server uses 12 megabytes of ram per thread (per page view at any given moment)

- It takes 1.5 seconds for each page to be generated (this is normally faster with caching, but I'll keep it simple)

Now, what I need to know is:

- How much ram my web server needs to not crash on me

- How much bandwidth my website will need to handle the traffic, not accounting for spikes

Since I'm feeling lazy, I'll let your students figure this out.

Things to keep in mind:

You must calculate how much data each page requires vs. how much traffic your site gets per second vs how much bandwidth your connection has vs. how much memory your web server has (this is important for slow connections)

A web server (normally) has a max of 32GB of RAM, so if more than ~30.5GB are used for web threads, you'll need a second server

## Elizabeth Gu

You know, I thought that most of the lessons that I learn from the math class seemed to be not useful to my future career--a writer, lawyer.

But these days, I regret it.

I was wrong--but not totally wrong since I still believe that my country's education system has too many problems. All of the students care about is just higher scores than they have right now, and the worse thing is some students tend to memorize all mathematical formulas just for the exams even if they don't understand the basic principles of them. That is, math we learn in the class is divorced from reality as if theory is separated from the practice.

If I had tried to find the beautiful value of math and studied more, I would have enjoyed the math class and tried not to obsess about the "score".

Btw,I think you are a very good teacher who has a great attitude toward your job and your students:)

love the way you ask about it.

## Gail G

Then I FINALLY left high school and, vowing never to enter another schoolroom, I began to learn the JOY of learning. This included the joy of math. Math, I discovered is not a bunch of boring formulas. Yes, those formulas are part of it, but they are a fun part of it. My change of heart came when I understood that math is a language – a language that tells stories as well as any novel can. It just tells different stories. It tells stories that do not lie – unlike most of all else that I had been told.

I found that teachers (and others) over-simplified and took all of the fun out of it. By making the object to learn what was expected, rather than to ask questions that math might be able to answer, my humanity was being devalued and diminished. I knew that my time was being wasted, and that insult to my integrity was deeply painful. It was a constant reminder of how fruitless it was to bother because there was no future in it for me.

Continued in next post:

## Leonard white

I tried to design the project to encompass as many of the subjects in the curriculm as possible. We covered ecology, history, art, theology, physics, biology, literiture, computer aided design, green screen technology, photography, woodwork, engineering and math. The sculpture is depicting the mythical creature the Chimera. After looking at the anatomy of three animals, lions, goats and snakes we were presented with the problem of how to interprate organic shapes using straight and flat peices of found wood. we had to break the structure down into simplified mathematical shapes .How do we create a tube for example ? we construct hexagons or octagons or decagons and build the illusion of a tube connecting flat planes. Mathematical equations had to be sketched out in chalk on the concrete to work out angles for these shapes. I believe that maths can be taught effectivly through practical design problems and physics.

I feel this aesthetic learning offers an intuitive, deeper understanding of the implications that these symbols we call numbers have on the real world.

http://www.facebook.com/photo.php?fbid=10150226399896201&set=o.225004870021&type=3&theater

## Bruno Carre

For kids, I'd guess this could translate into a "lemonade stand" where kids would be responsible to buy their raw materials then put a price tag.

At home, I dream of building a tree house with my son, which would imply simple calculations such as calculating the surface (how many wooden planks would I need for ... squared meters) and also geometry (angles).

Of course your question depends on the children's age.

PS: As far as your question is about making kids actually like maths, Jump math is an interesting new way of teaching and it seems to bring great results, even with kids "who are not good at it". Check this out here: http://jumpmath1.org/

Just for this, I wished I lived in Canada or the USA so my kid could be taught maths following this method!

## Martin Varhnis

1) Working with the ATF: Certain Criminal Organizations in this country hire lower/middle-class Americans to buy weapons and place them in trunks of cars for a cash stipend. An Organization-member will ask said normal, every-day American if they would like to make a quick $5,000. Economically unlucky American agrees: Takes the $25,000 offered by the Organization-member and buys $20,000 worth of semi-automatic rifles (under his name), places them in the trunk of a specified car and never sees the Organization-member or the weapons again.

Two years later, one of the semi-automatic rifles that the American purchased is found in a murder-scene in Mexico; the victim being, say, a VP of an important International Trade group. Now that serial number is tracked, through time of purchase allllll the way back to the American that bought it. Through that long process: statistics, physics, and even chemistry is used. Tracing such a thing over a long period uses variations of math by many different government agencies, like the CIA.

2) Working with the DEA/ICE: Narcotics have a simple way of finding sources. My example is cocaine: You can chemically and mathematically deduce the cocaine an agent picks up off of a dealer to tell how close to the source you are. If it's 100% pure, he is the source. If it's 75% pure, he's cut it up with less pure cocaine he has been selling as well. If it's 50% pure, you're even further from the source and said dealer has been cutting it up with the different providers he is working under.. etc etc. The further from pure, the further from the source. Find the source, you get to kick his door in and arrest him.

Good luck with this one David. Hope I helped!

## Jean-Pierre Walker

## Tom Hruschka

## Rikki Ansell

We have wonderful assessment tools that help us understand how personality types learn and interact. We should be using them to match students to the right teachers!

## Kevin Claiborne

As a math major, you might guess that I use math mostly when my girlfriend is out shopping with my money and asks me "what is 30% of 125 dollars?"

Of course !

## alberto tagliaferri

I found Math and Algebra empowered the mind with some ways of thinking you would not accomplished other way. I think one example is the first subtle and beaty concept I came upon: infinistesimals and the definion of function limit.

When a debate comes at work about some "yes/no" issue or some steps between that "yes/no", I always could see a continous of states and conditions in between. Money and time to implement seals the things and delimits what is feasable. But, sometimes is good to undestand issues and I beleave me being able to see this has something to do whith beeing able to see epsilon becoming as little as I want and always beeing able to find (a some cost, of course) a suitable 'h' that let's me approach as much a I wanted.

## Jason Kirin

It's all about behavior, mental and emotional stability.

And, of course, when I was in High School and college I griped through my math classes muttering that I'll, "never use this in my real life ever!"

I learned American Sign Language, Literature and Psychology- hooray for no math! I thought.

Now, math doesn't bother me-- I quite enjoy it now that I'm older.

But in my job I often have to use math for behavioral data collection. When one of my students has a negative or positive mark on their Daily Progress Narratives then it is calculated into a percent of their day, this data is then calculated into weekly updates and monthly updates. All of it turns into numbers and averages that are spread over graphs and Individual Education Plans.

In many cases the words are no longer even seen!

I'm fairly certain a lot of the psych field turns into numbers at some point or another.

## Yawa Hansen-Quao

## Jordan Kannon

To sum things up, using math as a proving ground for arguments will open up a whole new method of discussion. Expose your students to this and I am sure it will peak their interest in the mathematics.

## Obey No1kinobe

It's amazing how much money you can spend by saving money on discounted products.

## Kevin Choi

the LSAT, GMAT, GEM require math. Although it may not be calculus, it is the coherent logic that you have to compute (quickly) to solve many questions and problems. I was told that these math questions are involved in exams like the LSAT because it reflects your level of coherent logic. It makes you think on your feet, helps you theorize new ideas, organize information/data, etc etc.. Pro gamers, athletes, even most successful business have proven to have high computing capabilities.

## Abd Al-Rahman Hlayhel

But look around you math is everywhere every physiques formula is a probable example, who don't know the example of car A and B are racing,

A has speed x

B has speed y

B start ahead of A by distance d

How long will it take A to pass B

That's a simple physiques formula, could be used as an example.

Not only physiques there is biology, chimistry, programing, etc...

Math is everywhere in anything we use, even the sofa I'm sitting on is built using math

I can't think of anything not related to math, one way or the other.

One of math fascinating math implementation is in natural inspired algorithm

there is a software called netlogo with lots of pre programed examples, a bit hard for kids but can be used by the teacher in a session or two to given students some live solved problems

The software can be found here

http://ccl.northwestern.edu/netlogo/

## Yolanda Cai

## Ceri Jones Salahadyn

I learn through experience, so need to be able to apply in order to experience, in order to learn. My life food and passion is learning so I have created my life, to continue my learning through experience and in turn, create experiences for others that enjoy a similar palette.

"Making Ideas Tangible" through Working Art is how we do it. Our most recent structure intersects, Art, Architecture, Education and Renewables ="Interactive Hard Art". Every type of Math was used throughout the fabric of the Design, Construction, Installation and ongoing development as an Educational tool, functional sunshade and community Art element. We are working with the Principals and Teachers, inclusive of, Art, Science, Math, Geography and History to develop fully integrated curriculum and lesson plans (using Promethean Planet as just one of the mediums) that align to the IB program frames. The design holds ancient and universal truths, wisdom and knowledge, with an entrance through the Sun's highway and the 12 zodiac constellations that the sun passes through during its annual cycle. This piece of “Interactive Hard Art” exposes our young people to rudimentary universal knowledge in a playful, engaging, artistic and creative way that allows them to think and apply their unique expression to their learning process. The more we integrate meaningful learning possibilities through Works of functional Art the more we can demonstrate a Return on investment that allows for the production of more one-of-a-kind, considerate and bespoke, tools for our young people to become productive and creative global agents.

Integrating a rudimentary solar lighting system is next. An article published in "Go Green Kids & Parents" International Magazine can be reviewed on pages 5 & 6 at www.gogreenkp.com and for further information you can visit our dedicated project web site at www.interactivehardart.com.

## Connradd Tatge

Algebra will be enough mathematics to get one through the day (in America anyway).

All of that calculus, differential equations, linear algebra, discrete math, etc? Unnecessary!

The purpose of taking a math course is to qualify to take the next math course. Yikes.

## Vojtěch Pacík

## Johan Cegrell

It does not require that much arithmetic. But it does require a very acute sense of the creation and transformation of denominators and variables. You need to understand the math of the numbers and figures, without actually computing them.

Personally I don’t like to do math. But the understanding of mathematics allows me to be part in projects and issues that are both exciting and challenging. I can be part of and help guide operations whose mathematics I understand, but could never perform.

15 years after high school, I found the answer to the question I used to challenge my teacher with.

## Reilus Heliodromus

While you don't want to encourage careers in illicit finance, you might point out that people like the good folks at Enron and guys like Bernie Madoff can undertake complex mathematical schemes that get into astronomical numbers. You might lower your voice, squint at them, and ask them what other mathematical conspiracies might exist?

You could tell them to look into Japanese sumo and the system of cheating used in matches. One can prove its existence though statistical analysis. What other lies can one uncover beneath allegedly holy shrouds with mathematics?

Mathematics is the cornerstone of the Quadrivium -- mathematics, geometry, music, and astronomy. Mathematics presents the number, which is an idea that exists outside space-time. Geometry puts the number into space. Music puts the number into time. Astronomy puts the number in space-time. That might fascinate some students.

## M Voelker

## Rachel Koser

## Tony Kuphaldt

Microsoft Excel (or any spreadsheet for that matter) is another way to integrate real-world tools with mathematical education. Applying algebra to get a spreadsheet to do the calculations you want it to, or using a spreadsheet to visually represent data, is a powerful thing. I have my (2-year technical) college students use Excel regularly as a mathematical modeling tool.

One of the most memorable examples of math education for kids I've seen is my fifth-grade teacher, who had us building model rockets and using trigonometry to estimate how high they flew. First, we would stand 100 feet away from the launchpad, sight the apogee of the rocket using a special protractor, then look up the value of the tangent of that angle (this was in 1980 -- we used trig tables rather than hand calculators) and multiply by 100 to find the rocket's height. Very cool stuff, and it took all the fear away from trigonometry when I encountered it much later in school.

## Tony Kuphaldt

One example that comes to mind is a diagnosis I once made on a leaking compressed air system at a commercial facility. Compressed air was leaking out of the pipes somewhere in this expansive system, but we did not know where. We connected a pressure sensor to the main pipe and used a computer to graph pressure versus time. This revealed an inverse-exponential curve, which is precisely what you would expect if the air pressure at the leak were falling with time -- an air leak occurring at some location where the leak pressure was constant would produce a linear drop of main supply pressure over time (based on differentiating the Ideal Gas Law: dP/dt = dn/dt R T / V). We knew this system had pressure-regulated as well as unregulated segments to it, and from this analysis of the pressure drop we could tell the leak must have been in one of the unregulated segments of piping. This knowledge allowed us to eliminate large portions of the piping and focus our search on a smaller part of the system, to find the leak faster than if we searched the entire piping system.

A subset of mathematics education is estimation. A person who can rapidly estimate quantities is able to apply basic arithmetic to a wide variety of problems in life (time to arrive at a destination, costs versus returns of financial decisions). An understanding of probability is crucial to making intelligent decisions involving risk and reward. As I like to tell my students, lotteries are a form of taxation on the math-illiterate.

Simply put, math is a powerful tool for understanding the physical world around us. Who wouldn't want to have a powerful tool at their disposal to help them make good decisions in life?

## Tony Kuphaldt

* Fourier analysis of waves: Jean Baptiste Fourier discovered that any repeating waveform is mathematically equivalent to a series of sinusoids (sine and cosine waves) added together at different amplitudes, phase shifts, and harmonic (integer-multiple) frequencies. When you look at a graphical equailizer on a stereo system and see the individual bargraphs showing how much of each frequency comprises the sound, you are seeing the results of a Fourier transform function applied to that wave. Fourier transforms work for *all* waves, not just pressure waves (sound). In machine vibration analysis, for example, technicians and engineers use Fourier tranforms to decompose a vibration waveform into its different harmonic frequencies, those decomposed signals holding clues about the health of the machine.

* Charles Proteus Steinmetz applied the notation of imaginary (vs. real) numbers to the solution of alternating-current electric circuits near the turn of the last century. His mathematical contribution to the then most empirical subject of electrical engineering revolutionized the field. As it turns out, complex numbers work wonderfully well to represent electrical signals (there are those waves again!) changing in time. Technicians and engineers in the electrical industries use Steinmetz's principles continually to calculate voltage and current quantities in power systems.

* The calculus principles of integration and differentiation are widely used in automatic control systems. Differentiation is used to calculate the rapidity of some variable's change, for the purpose of damping rapid changes. Integral is used to calculate how much control action is necessary to bring a variable back to its "setpoint" (target value), by integrating the error (variable-setpoint) over time. Technicians and engineers "tune" control systems by adjusting the coefficient multipliers of the differentiation and integration functions to achieve stable control.

## nagib shagour

is there any design behind the shape of the digits as

written in the English alphabet. namely 1234567890

to see that please write the digits using straight lines.

the design is that the shape of every digit indicates

its value by an equivalent number of "angles".

1 has only one angle. 2 has two and 3 has three

angles. Try out the rest of the digits 4 5 6 7 8 9 0

its interesting i think.

## Krisztián Pintér

1 and 7

## nagib shagour

1 has clearly one angle pointing to the left. just remember its 1 not "I"

and 7 remember how we used to write it before the digital calculator came about.

7 with the small horizontal dash in its middle.

I still don't remember the exact shapes of 6 and 9.

## han jinyu

## O'Neil Poree

I particularly enjoyed, and used feedback control technology (Start with Norbert Wiener's classic "Cybernetics" for a good orientation there).

Then there was numerical analysis, particularly numerical integration. Skim through calculus to motivate that, and go for the references to pioneers: Runge, Kutta, Simpson (all of these will have "Rules" quoted in the literature).

Finally, one needs dynamics and mechanics to get into really fun work, like putting a missile from, say, Hawaii launching down next to a given site on Luna, (or Mars, or such...).

Showing such possible future undertakings as these, to interested students, will fire some of them up to "blast off", I would guarantee.

Enjoy.

## Carlos Carvalho

We collect usage data from every interaction and then we mix and match all the data through (usually basic) statistic models and use a lot of perception.

"Is this prompt too long (as the client would become impatient?)"

"Is this menu confusing? Where are the clients going?"

"How can we improve the overall experience of the user?"

"How can we tweak phrasing so it will result in better understanding of the companies process?"

Those are questions that we try to answer every day. We gather data, treat it, count, group, calculate and forecast.

The numbers gives us the power of being creative, but effectively, since we are able to test and prove the results of something that otherwise would be a guess.

So, we try to understand this part of the world and people through many mathematical forms. Oh, and it's always awesome to know that you're changing (hopefully for better) this little aspect (how they connect with companies, have their problems solved, buy things and voice complaints) in the lives of millions of people each day.

## Comment deleted

## Krisztián Pintér

## Edward Webber

Just as one should not stifle pointing out the dead end in ideas.

"perhaps one should admire the work and artistry behind the comment"

Perhaps you should admire the creative approach he used to respond to such an obvious dead end theory instead of complaining about it.

## Beverly Coursey

## Michael Hennigan

## nagib shagour

http://www.wolframalpha.com/

## Megan Geckler

I believe that my colorful work especially appeals to kids, teens and young adults - feel free to show them some of my projects, we also have a vimeo channel that shows the teamwork that goes into making such precise massive works of art. In the next few weeks, my website will be changing to include schematic architectural drawings and diagrams that we develop during the planning stages and use as working charts during installation. So keep checking in :)

## hossein karami

## hossein karami

## Robin Patin

Math has most often come in handy with big ticket purchases and investments that requires someone to calculate out monthly payments and interest rates. When I was buying my first car, the dealer miscalculated my interest rate and quoted a monthly payment about $20 a month higher than it should be. I caught it immediately. He said that $20 per month wasn't such a big deal. I retorted that $20 per month puts an extra $1000 or so bucks in HIS pocket over the life of a five year loan. That's a very big deal.

Unless you can calculate out compounded interest, monthly payments, and simple interest rates, you will be taken advantage of at some point when buying a car, buying a home, or investing.

## Beste Arslan

## David Semitekol

Thanks again and keep them coming!

## W T

I need an understanding of number order to find addresses as I drive around town.

I need mental math to calculate which is a best buy at the groceries. If a 24 ounce package is on sale for $4.99 is that a better buy than say two 12 ounce packages that each cost $2.65?

I need it to scale down a pancake recipe I have that feeds eight. Some mornings I only make pancakes for 4 or 5 people, so I need to divide fractions for this.

Math is very important!!

By the way David, are you familiar with Project M.I.N.D. (Math is not difficult)? It was started as a grant project by a Nova University professor many years ago. I don't know if it is still around.

Also, here is something I used to love to do with my little ones each morning.(kdgtn and 1st grade)

Calendar Skills: Let's say today is the 28 of the month. I would ask them to make 28 using coins. I would ask for three ways (1 quarter 3 pennies, 3 dimes 1 nickel 3 pennies.....etc)

Kids really looked forward to this each morning.

When learning fractions, we would make pizzas out of construction paper. I precut the paper into huge circles beforehand, they decorated and made their own paper toppings,

They had to divide the pizza up into 1/2's or 1/3's or 1/4's and then choose toppings, Later, they had to write about what they did. For example....My pizza is one third pepperoni, one third cheese and one third mushrooms. I always found that taking a Math enrichment activity and turning it into a writing assignment really paid off.

Afterwards, I filled a bulleting board with all their colorful pizzas and writing.......I loved to decorate my class with kids work.

How about you?

## David Semitekol

Thank you for the link for project M.I.N.D. I will have to take a look at it.

I love your real world examples with your kids. My area of interest is in college math and higher, perhaps starting with high school. For example: algebra, calculus and trigonometry.

My concern is with the student's interest when approaching these subjects. They simply have no desire to learn the material and they end up just muddling through it. In some cases it causes students to change their major just to avoid the required math.

There is a difference between having to learn something and wanting to learn something. When we have to learn it we just try to get through it. When we want to learn it, this is when we make breakthroughs. Stimulate the interest in students so that they want to learn math and we increase our probability in someone discovering the next breakthrough.

## W T

Because if you do, then the possibilities are endless. The board allows you to display any website on it....so if you do your research, then you'll always have a great opening for class.

The internet has made teaching much more interesting for the teacher and the student. But still, it is the teachers integrity and devotion to the subject matter and his students that decide the outcome.

Also, remember about www.kahnacademy.org. Teachers, as well as students have access to free tutoring sessions. You might pick up some ideas on how to present your material there.

I wish you all the best David!!!

## Krisztián Pintér

last time i had to solve a linear equation system. decided to use LU decomposition, just for the sake of it.

i often have to work with dates, ie, what is the closest thursday of a given day. it involves modulo 7 arithmetic, and occasionally ceiling / floor function.

sometimes rounding tasks come up, which involves logarithm and ceiling / floor. (like: round number to have 3 significant digits, like 121 or 655million or 0.000615)

business calculations tend to contain trend-fitting. linear and exponential trends are very common. example question: what is the anuual growth % if the value went up from 1000 to 1300 in 3 years (hint: not 10%).

## O'Neil Poree

## Leonard white

## B T

And I cannot remember a day in my life when understanding mathematics was not as important in my non-working life as my ability to use language. Does anyone think they can buy a car, a home, borrow money, shop at a store etc without having a quantitative understanding of what they are doing?

So you can try to scare the Hell out of them:

Without math (unless you are among that tiny number of people who are very talented, creative or beautiful, or a criminal) you will probably, for your entire life:

1. Not get a job that pays enough for you to lead a comfortable life, with a nice home, nice car, nice things for your family etc

2. Not be a smart consumer and probably be taken advantage of when you buy things or borrow money

3. Not be able to effectively invest your earnings to accumulate wealth

4. Not be able to easily understand the increasingly complex world that you live in which is dominated by science and economics.

On the positive side:

1.Show them how their passions and interests are tied to math. Even if you are an artist or a writer, you still need to understand the concept of value and how to quantify it.

2.Take them through the days of people as they go through their lives, buying things, understanding current events, understanding money, undestanding calories, understanding the climate. etc.Almost every important decision they make in their lives will be done better if they understand math.

3.Give them books to read that have quantitative as well as qualitative content.

4.Have them play games that require math (Monopoly ?)

5. Pair up, or group, students with low math interest/skills with those who have high interest/skills

Good Luck