# What is the difference between * and x

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 "÷"

-
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
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

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.