4A. math (+ - * /)
These infix operators combine an expression with another value
to yield a new value. Examples:

1+2, MAX-1*5

(see  12A  on how to overload these operators for use with floats).
"-" may be used as the first part of an expression, with an implied 0,
i.e.    -a    or    -b+1      is legal.
Note that * and / are by default 16bit operators: (see  9G , Mul())