Multiplication sign
There are several symbols that are used as multiplication sign.
Explanation
Everybody knows the multiplication tables, and so you know immediately the outcome of
Often you don't even have to write a multiplication sign, because everything is clear enough, as with
and you must therefore describe it as: x times x plus 4. Also the simple notation
is a multiplication, because it means: 3 times x. Rather tricky is
because here you multiply 156 with √6 and with x. But after some time you won't notice this anylonger and even a difficult term poses no problems, just look at
Other notations
Mathematicians prefer to write the multiplication sign as a point, to avoid confusion with the letter x, so
x · x instead of x × x or even x x
Sometimes you must use an asterisk (∗) because a point has the meaning of 'decimal point', and then you get
On calculators, smartphones and tablets you will normally see a × key, sometimes also a ∗ key.
HistoryThe multiplication sign (×) is very old. It comes from India, where it was created after the frequent use of cross-multiplication, as in where you start to calculate from top left to bottom right |