## Simple but profound

Posted by itheabsolute on February 7, 2006

Long time ago, an anthropology professor asked me why human beings are most comfortable with multiples of 5 or 10 and not 3 or 7 or 9. I found the question to be quite naïve and struggled to come up with an answer. It may have been an accident or some fancy of a scientist or someone important liked the numbers 5 or 10 over 3, 7 or 9. The answer surprised me. Human beings have 10 hand fingers. Counting was easy when the number of fingers, 10, became the basis of counting. Simple, but profound.

Answers to many issues that puzzle us can be as simple, but we generally refuse to see what is obvious.

In the same context, I liked this quote – Everything has been said before, but since nobody listens, we have to keep going back and beginning all over again – Andre Gide

## itheabsolute said

bbird

all the best

cheers

## bbird said

Hi Vijay

Thanks to you ! Cheers and all the best for your placements !

R1 admit

## itheabsolute said

dinesh & bbird

good discussion.

cheers

## bbird said

Yep! This completes the cirle

Perhaps this would make it more clear

in Base 14 system

7 x 1 = 7

7 x 2 = 10

7 x 3 = 17

7 x 4 = 20

and so on …

( where 10 would have represented the count from 1 to fourteen ,

and 14 would represent Eighteen )

The question is ..Would we have selected decimal counting system if we had fourteen fingers

## Dinesh said

bbird, brings up a critical point I missed.

If we were using base-14 system then, yes, multiples of 7/14 will be easier to count in. Had we 14 fingers, we may have, after all, used base-14!!

So, in conclusion, I think the anthropology professor was trying to explain why we evolved to use decimal system(base-10) rather than, say, base-3 or base-7 or base-14. (The ease of counting in multiples of 5/10 being a direct consequence of the decision to use the base-10 decimal system).

## bbird said

How about if we used a Hexical system or base 14 system instead of a decimal system . Then again what if we had 14 fingers or six fingers… who knows …

😉 😉

## Anonymous said

Wow, that is simple but very profound.

## Dinesh said

I’m not sure I agree with the anthropology professor.

It surely has to have something to do with the ease of 5/10 multiplication table (multiples end only with 0/5) as opposed to 3/7 (multiples may end with any digit from 0-9).

Even if human beings had evolved with fourteen fingers, I think they would have still evolved to be more comfortable with multiples of 5 or 10 than with multiples of 7 😛