With arithmetic operators

If any operand can be null, the result can be null. If any operand has the null value, the result of the expression is the null value.

If one operand of an arithmetic operator is numeric, the other operand can be a string. The string is first converted to the data type of the numeric operand and must contain a valid string representation of a number.

The prefix operator + (unary plus) does not change its operand. The prefix operator - (unary minus) reverses the sign of a nonzero non-decimal floating-point operand. The prefix operator - (unary minus) reverses the sign of all decimal floating-point operands, including zero and special values; that is, signaling and non-signaling NaNs and plus and minus infinity. If the data type of A is small integer, the data type of - A is large integer. The first character of the token following a prefix operator must not be a plus or minus sign.

The infix operators, +, -, *, /, and **, specify addition, subtraction, multiplication, division, and exponentiation, respectively. The value of the second operand of division must not be zero, except if the calculation is performed using decimal floating-point arithmetic and the first operand is infinity or -infinity.

In COBOL, blanks must precede and follow a minus sign to avoid any ambiguity with COBOL host variable names (which allow use of a dash).

The result of an exponentiation (**) operator is a double-precision floating-point number. The result of the other operators depends on the type of the operand.

Operands with a NUMERIC data type are converted to DECIMAL operands prior to performing the arithmetic operation.