With that in mind, let a, b and c be three real numbers. Examples Note that negative numbers are sometimes enclosed in parentheses to avoid confusion between the sign of the number and the addition operation. There are obviously several different notations in use, depending when one learns it and what context one learns it.
Multiplication follows the same two laws just described for addition.
We are following the same convention as with addition. Thus, we need some sort of symbol to make the two distinct. Experience with the notation will help make it very clear what is meant. This looks a bit neater. Again, such things are a matter of style, and the reader is encouraged to use whatever bracketing makes the most sense and allows clear, proper ordering of calculations.