Definition of arithmetic facilities

A precise definition of the arithmetic facilities of the REXX language is given here.

Numbers
A number in REXX is a character string that includes one or more decimal digits, with an optional decimal point.
Precision
Precision is the maximum number of significant digits that can result from an operation.
Arithmetic Operators
REXX arithmetic is performed by the operators +, -, *, /, %, //, and ** (add, subtract, multiply, divide, integer divide, remainder, and power), which all act on two terms, and the prefix plus and minus operators, which both act on a single term.
Arithmetic operation rules: basic operators
The basic operators (addition, subtraction, multiplication, and division) operate on numbers as follows.
Arithmetic operation rules: additional operators
The operation rules for the power (**), integer divide (%), and remainder (//) operators are described.
Numeric Comparisons
You can use any of the comparison operators for comparing numeric strings.
Exponential notation
Exponential notation is useful for both large and small numbers.
Numeric information
To determine the current settings of the NUMERIC options, use the built-in functions DIGITS, FORM, and FUZZ.
Whole numbers
Within the set of numbers REXX understands, it is useful to distinguish the subset defined as whole numbers.
Numbers used directly by REXX
As discussed, the result of any arithmetic operation is rounded (if necessary) according to the setting of NUMERIC DIGITS.
Errors
Two types of errors can occur during arithmetic operations.

Parent topic: Numbers and arithmetic operations