Take the 2-minute tour ×
Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. It's 100% free, no registration required.

For PC calculators you use * instead of x, or / instead of ÷. Why were these two symbols chosen over the other two?

In the standard Windows calculator, even the button uses "/" instead of "÷"

share|improve this question
3  
Because x is often the name of a variable, so using * for multiplication prevents confusion, and we don't want to introduce new keys to have a new key, $\times$, when we already have *. Similar with /. –  Arturo Magidin May 23 '11 at 19:45
    
@Atruro I run calc.exe and I can't create variables. –  Chris S May 23 '11 at 20:00
2  
It doesn't matter; the point is that in early computer programming, x was a character, not a mathematical operator, and it's a character that is too easy to confuse with the mathematical symbol $\times$. You want a symbol which is easy to differentiate (for debugging purposes) and unambiguous, so the closely related * was chosen to denote multiplication. Neither $\times$ nor $\div$ were standard keys in standard typewriters, which made them difficult to add to early computing (typewriters used x). It keeps going from there. Do you have a $\div$ key on your keyboard? I don't. –  Arturo Magidin May 23 '11 at 20:06
    
@Arturo I thought it may have an interesting mathematical reason but it's just the boring old restrictions of ascii –  Chris S May 24 '11 at 8:52

1 Answer 1

up vote 2 down vote accepted

I don't know which came first in this case, but I'd have to believe it came from using $\cdot$ for multiplication in writing and $/$ came from the fraction symbol.

share|improve this answer
1  
I'd have to comment... –  The Chaz 2.0 May 23 '11 at 20:05
1  
@The Chaz: But I can't for lack of stupid rep! –  t.b. May 23 '11 at 21:40
    
@Theo: Do you have a website or links to any projects you've worked on? (I understand if you prefer privacy) –  The Chaz 2.0 May 24 '11 at 1:42
    
@The Chaz: I wouldn't use my real name if privacy was my concern here. Googling my name should bring up my old and neglected homepage in Göttingen with some texts I wrote some time ago. But be aware that I'm neither this guy nor that guy. Currently I'm at ETH Zürich. –  t.b. May 24 '11 at 8:09

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.