- Paul Szabo
- Seattle, WA
- United States

Sr. Systems Architect,

This conversation is closed.

## You need to be able to calculate in your head

Imagine I'm sitting in a room with some fellow engineers, going over some recent test results on a new product. (This happens a couple of times a month at work BTW).

Conversation 1: (If you can't solve basic linear equations in your head:)

Eng1: "Data point X and Data point Y are in contradiction, there must be a measurement error"

Eng2: (spends 20 seconds on a calculator or wolfram alpha distractedly typing stuff in, or is he reading his email and ignoring everyone?)

Eng3: "is he right? I'm not sure. We should answer this at the next meeting"

Eng2: (after 20 seconds of tapping) - "yes he is. Now what?"

Conversation 2: you can solve basic linear equations in your head

Eng1: "Data point X and Data point Y are in contradiction, there must be a measurement error"

Eng2: 3 seconds later "yes, you are correct"

Eng3: "I know what must be wrong with the measurement. If we interpolate..."

See the difference? The human-computer interaction is *slow*. The interaction in your head is substantially faster. You can't carry on conversations with others if they are constantly referring to an electronic device.

For those of you who gamble to win, the same applies to poker. You have so many seconds to decide. Even if they allowed the use of a calculator or computer, it would be too slow, you have to do it in your head.

Maybe this doesn't have to involve using paper. But learning all the basic arithmetic tables is prerequisite, as well as the other basic arithmetic calculations.

This is the reason that Feynman forced himself to be able to do basic calculations in his head. Everything goes faster allowing you to iterate to a solution quickly. (He originally did it for gambling BTW!)

--Paul

## Chris Ke-Sihai

The inability of people around me to calculate, for instance, the correct change from my purchase, is a source of constant irritation to me. On the other hand, I can't juggle.

## ranjix ranjix

I'm also fairly confident that the average person can't calculate the change for an "average" publix bill (think some 20+ items, add some discounts and pretty sure the mistakes are not far).

So don't really see your point.

## Andrew Wharton

Quick example: My wife was buying medicine at the pharmacy for our twins a couple of days ago. They needed 4 doses each of 1.5mL, and the pharmacist told my wife that 1x20mL bottle would not be enough and she would need 2 bottles, which she just accepted without a second thought.

Needless to say, we now have an extra unopened bottle of medicine sitting here and I doubt they'll give us our money back for it... It's a simple example, but I think it illustrates my point.

## Sidney Whitaker

## Debra Smith

## James Horton

For the work field, I still agree that speed and efficiency are needed. Think about it, your boss asks you and a peer to do something, but you do it in your head while your peer does it on a calculator. You finish two minutes faster, now all of a sudden your work is exemplary, despite whether your peer has done the exact same thing. Say, "Hello Promotion"

I agree, nice point. :)

## Peter Angelo

## Milya Caghun

## Scott Staples

## Victor DeCaria

## Wesley Clawson

I'd like to hear your thoughts.

## Renee Lascala

"How did you get that?" as if I'd found a concealed object; "How did you know what to do?" as though I'd glided into the cockpit of a jet and, untutored, safely landed it in darkness.

These are the responses I get from basic math operations. Calculations involving a variable or carried out to 3 decimal places are regarded as my particular brand of witchcraft. I've resorted to using The Money to set forth what one must expect in the metric system. And stifled screams when asked "A milligram is just like a microgram, right?"

The lowest of low water marks for me was when someone teaching others asked me to calculate the change in concentration of an intravenous liquid when half had been infused into a patient and half remained in the bag. I am a Doctor of Pharmacy, and sadly must explain it is nurses and physicians, all too often, who ask such questions. In response, I never, never express scorn, and I admonish you, TED readers, who may be gifted and practiced in mathematics, to do the same with those questioning you.

I had to learn, to internalize. You did too. Perhaps it came a bit easier to us, but we must not use this as justication for cruelty. You see it's a combination of what must be some terrible foundations, aversion and anxiety here. Add shame to this and another generation of arithmetic have-nots will be begotten.

The inability to estimate, the absence of the capacity to notice an answer looks wrong--- can and does kill. Let's do all we can to make "Easy for *you*".....just "easy."

## Alexander Wiedemann

## Chris Dimick

## ranjix ranjix

"This happens a couple of times a month at work BTW" - so, using your advice, you would save at work 20sec x 2times a month. Fantastic, you saved 40sec this month. /sarcasm.

## Revett Eldred

## ranjix ranjix

## Revett Eldred

## ranjix ranjix

## mark kausche

## Jonathan Fernandez puga

While I agree with you in some aspects, efficiency and patience. I thought about this for a bit, and noticed that I have a tendency to "google" a lot (or using any tools to find the answer, its relevant). And I can not specify on how often I repeat some 'googles' but I am sure they happen. Same as how often Eng:2 has to type in the same equation with different numbers.

The point I want to make is - It is not so much the fact that one has to refer to a tool, but what the person will do once he has that answer. How will it be implemented, what changes etc. etc. While I find the importance in someone being able to quickly calculate and save time. I find it more valuable for that person to find better solutions or ideas to said topic.

In your second example you assume that because one is able to calculate, one can up with an instant solution it better, The 3rd engineer quickly responded by looking for a solution, giving a suggestion. While in the first problem, after time wasted "now what?" or... lets do it next time. This can be a lot more frustrating. Hope I didn't take it too far out of context.

Can we say that because Feyman could do basic calculations in his head it made him a great mind...? Although I agree, we should strive to be like those.

## Leah Warfield

My daughter actually has mild learning disabilities, one of which is a problem with processing and memory. One of the things she struggles with is basic math computations. For years, though she is in a special education program for math, the school system insisted she attempt to memorize the multiplications tables despite her documented disability in this area of learning. What is the point of that? In a technology based society, she will never be without a calculator so why attempt to force conformation to a particular learning model, when her particular disability can so easily overcome with a cell phone?

## morning Ellergrace

I think this postulate imposes a bit of Mega-rigor-istic ideology...Which is great ... if you are a mentat or a scientist.

I am a programmer so I am not bad at auto-calculation but must but must admit that I need allot of work. Hey, Eisenstein didn't memorize phone numbers... I'm just trying to say ... Who you are is at least partly a product of your needs... your environment.

This seams like more of an argument concerning identity and I don't have any opinion on it.

## malcolm bellamy

## Bill Harrison

## Haitse Auke

Mark a few chemistry papers and you will see what I mean.

## Matthieu Miossec