Multiplication sign, using '*' or 'x'

• Sarawut Positwinyu

10 years ago

In mathematics, the operators provided on keyboard are quite clear for addition, subtraction and divide: + - /.

The multiplication sign * might be familiar as the multiplication for programmer, but I'm not sure about ordinary user. I don't know if I should use * or x for multiplication.

The purpose is to provide user detail of how each field will be used: One drawback I can think of is if using x might rely on font face and if user changes the font, x might not be appear like multiplication sign.

Also, by the standard * (asterisk) should be used to multiplication, but I'm not sure about its readability. I always had the impression that "*" was used as a multiplication operator because "•", commonly used in algebra, was hard to find on older (particularly PC) keyboard layouts, but looked similar enough to be interchanged. I am not confident that * is a good multiplication operator for human consumption. Please don't expect users to actually calculate the rates themselves! (Room Price + Charge) x Net Rate %, ... @Wousser That is just a description of how each Apply Type will be used to calculate. The program will do it. Why not use `×`? @hippietrail at the time i was writing this question. i didn't know that sign existed :) Thanks good reference for other codes https://dev.w3.org/html5/html-author/charref

• 10 years ago

It would certainly be a mistake to use the letter x as the multiplication symbol as x itself often denotes an algebraic term:

e.g. compare

x x y = c
x x y = c

vs

x × y = c
x × y = c

The &times; or &#215; or &#D7; character looks like this: × so it is a proper cross, as opposed to the letter x (ex) or * (asterisk) symbols which are a lazy approach and don't create symmetrical symbols about the major axes.

The &times; version is simply the friendly version of the same code.

For additional reference, for divide you can also use &divide; or &#247; to get ÷

For minus you might expect to use direct from the normal key, but there is a separate code for that too &#8722; − which aligns it vertically with the keyboard plus symbol, so you get ( −+ −+ ) instead of the keyboard minus and plus, which may not be aligned depending on the font ( -+ -+ ).

You can get the plus/minus via &plusmn; or &#177; ± .

There is another Wikipedia entry for the symbol itself, which currently consists of the information below:

(sorry, this is an image - so links are not real!)  Would be kind of nice if those were the symbols you got when using the keys on the numpad. @Svish You mean pressing '/' would give you ÷ and pressing '*' would give you ×? Looks to me like you're raising X to the X then multiplying by Y There is a semantic difference for multiplication on non-scalars. For vectors `A × B` (cross product) is not the same as `A ∗ B` (dot product). Ah, I never knew there was a Unicode for either the '×' OR '÷' symbol. (Well, TBH i've never really looked). Now I know. also, don't forget to use `∗` (∗) instead of an asterisk (*) @root45 exactly. except the keys should have the correct print too of course. and calculator software etc etc should react appropriately and such... Roger, is there a better alternative to using the < and > keys on the keyboard? got them. < < < < for "less than". > > > > for "greater than". https://dev.w3.org/html5/html-author/charref