# Mathematicians and Basic Math

1. Oct 17, 2004

### Chrono

I keep hearing about mathematicians not being able to do basic math. I mean, that they have trouble balancing their checkbook, or can't figure out a 15% tip. Is there any reason for this? I'm thinking that it's just too basic for them. Thoughts?

2. Oct 17, 2004

### Tide

I believe your premise is in error! :-)

3. Oct 17, 2004

### Janitor

Balancing checkbooks is more a matter of discipline, and some mathematicians may not possess that in quantity. But I doubt any mathematician would have difficulty approximating 15 percent of a number in his/her head.

4. Oct 18, 2004

### robert Ihnot

Mathematicians are know to make simple mistakes on the blackboard while discussing their work. There is story that comes out of "Racing for the Bomb, General Leslie R. Groves, the Manhattan Projects Indispensable Man."

A General, much to the horror of the scientists, was put in charge of operations. This General antagonized the scientists by telling them that he had learned the calculus on his own. He also claimed that through self-study he had acquired the worth of two PhDs.

In October 1942, General Groves caught an error on the blackboard which came about from failing to correctly copy a figure from one line to the next. Groves then spoke up and told the scientists about it. While Groves might have believed that he was being set-up to look like a fool, he went on with his remark about the calculus and how he ought to have been awarded two PhDs.

After Groves left the room, nuclear scientist Szilard exploded, "See what I told you? How can you work with people like that?"

Szilard is credited with explaining the idea of the chain reaction to Einstein. Goves said of Szilard, "The kind of man that any employer would have fired as a troublemaker."

Groves said that he wanted a noble prize winner to head the civilian end of the operation, because a noble prize winner in physics is the equivalent of a General in the Army. Groves originally wanted all scientists to wear a uniform at work, but Oppenheimer balked and said, “It would result in the loss of scientific autonomy.”

Last edited: Oct 19, 2004
5. Oct 18, 2004

### Integral

Staff Emeritus
There is a lot of difference between arithmetic and Math. Accounts do arithmetic, mathematicians do math. Balancing a check book is account work, it has little to do with mathematics.

6. Oct 18, 2004

### fourier jr

figuring out a 15% tip isn't math, it's arithmetic. by about 3rd year of a math degree people are beyond calculating things, and it;s more about abstract concepts and why things work the way they do. It's like Morpheus saying to Neo, "welcome to the real world" Real math (pure math anyway) is much more like philosophy since it's more about concepts than a science or calculuations, I think.

7. Oct 18, 2004

### Zurtex

Basic maths, real basic maths like solving the root of $ax^2 + bx + c = 0$ is something that mathematicians remember for a very long time. Unlike other subjects were bits are forgotten a lot of maths is built on knowing more elementary maths and so on and so forth, so knowing bits like is useful the whole way.

8. Oct 18, 2004

### Chrono

I like what you said here. At leat now I won't feel so bad when I take five minutes to add or subtract.

9. Oct 18, 2004

### pig

It's not that mathematicians are more likely to make mistakes, but people who didn't study anything math-related tend to think it's a big deal that a mathematician made such a mistake so it gets noticed more.

10. Oct 18, 2004

### PerennialII

Yep, I'd go along with this. Just by spending your days doing math does not make you immune to petty mistakes nor does it provide you superb arithmetic skills. Its actually sometimes quite neat how serious math guys solve elementary math problems their "own way".

11. Oct 18, 2004

### MiGUi

I think that is a more powerful tool learn how to do the things, instead of memorize them.

For me, is irrelevant to know the 15% of 75 if I know the math it in case I need it. And instead of 15% I would have said the calculation of a complex integral. Probably I would need a book to remind me how to work out it, but if I learned it in the past, I will be able to do it in the future. I am pretty sure of this.

Brain is not unlimited, and the less important things we remind, the more birthdates we will be able to memorize :)

Last edited: Oct 18, 2004
12. Oct 18, 2004

### JasonRox

Entirely true.

Archimedes was known to forget things like eating and sleeping. Same with Einstein.

Honestly, if God (if he exists ) said he will give me the power to know everything that is going on right now (including everything in all the journals ), and all I have to do is lose the ability to remember names (including gf's name), I would.

I mean, who wouldn't.

A mathematician chooses to not care about 2+2=4, but chooses to understand why 2+2=4.

13. Oct 18, 2004

### Chrono

I like this.

It must be a generalization about mathematicians that the know and can do everthing mathematically; from simple arithmetic to the most advanced thing out there.

14. Oct 18, 2004

### The Bob

It does annoy me when people cannot do simple mathematics when it is more or less answered for you in the question.

What is this world coming to?

15. Oct 18, 2004

### JasonRox

To an IQ of 2+2=3.

16. Oct 18, 2004

### Chrono

What kind of questions you mean, Bob?

17. Oct 18, 2004

### Gokul43201

Staff Emeritus
I'll have to disagree with the original post. Mathematicians may be reluctant (even abhorrent) to balance checkbooks, but they certainly will calculate a 15% tip better and faster than the average person. However, they may sometime use methods which on a rare occasion may lead to a stumble.

Let me give you an example :

I'm no mathematician, but I like to convert degrees F to degress C {C = (F-32)*5/9} using a bit of a numerical approximation.

I find it faster to calculate the result (to the required extent of) $(F-32)[\frac {4.5}{9} + \frac {0.45}{9} + \frac {0.045}{9} +...]$ than to divide by 9 and multiply by 5. Occasionally (actually, this happended once, and ONLY once), this will cause me to say something like F=59 (so F-32 = 27) implies C is nearly 15...when in fact it is exactly 15.

18. Oct 18, 2004

### JasonRox

Only once of course. ;)

19. Oct 19, 2004

### cepheid

Staff Emeritus
I don't understand...how do you use that numerical approximation method, and how is it faster? (Especially in your head!)

20. Oct 19, 2004

### The Bob

Well there is a simple chemistry question that uses simple mathematics:

The relative atomic mass of antimony is 121.75. Antimony exists as two isotopes, antimony-121 and antimony-123. Calculate the relative abundance of the two isotopes.

Now all you have to do is make an equation to work the relative abundance and use simple algebra to rearrange the equation and get an answer. My class knew how to work the relative abundance when the percentages were given but now that one percentage is missing and they have the relative atomic mass they are stuck. Also they can't handle two negative numbers on either side of the equals sign.

How simple is that question? Really??? Only three people in the group got them right. Then there are simple maths question, but if you want them I will post them later.