Futurebasic/Language/Reference/mod

MOD Syntax remainder = expr MOD modulus Description The MOD operator subtracts from ABS(expr) the largest multiple of ABS(modulus) which is less than or equal to ABS(expr), and returns the result as remainder. If expr is negative, then a negative result is returned in remainder. Note that if expr and modulus are both integers, the result of MOD is just the remainder of the integer division operation expr / modulus. See Also Appendix D: Numeric Expressions