You can combine character strings that are
valid numbers (see Section 1.10.4.5, “Numbers”)
using the following arithmetic operators:
+
Add
-
Subtract
*
Multiply
/
Divide
%
Integer divide (divide and return the integer part of the
result)
//
Remainder (divide and return the remainder—not
modulo,
because the result can be negative)
**
Power (raise a number to a whole-number power)
Prefix -
Same as the subtraction:
0 - number
Prefix +
Same as the addition:
0 + number
See Chapter 10, Numbers and Arithmetic
for details about precision, the format of valid numbers, and the
operation rules for arithmetic. Note that if an arithmetic result is
shown in exponential notation, it is likely that rounding has occurred.