Mod

Mod

Mod[ m, n ] returns the remainder when dividing two integers.

Usages

Mod[ m, n ]

Mod[ m, n ] returns the remainder when m is divided by n. The remainder is always between 0 and |n|-1, also for negative numbers. The result is 0 when n divides m, so Mod is often used to test divisibility.

Example in out
17 = 3 · 5 + 2. Mod[ 17, 5 ] 2
5 divides 15. Mod[ 15, 5 ] 0
A negative number: -8 = -3 · 3 + 1. Mod[ -8, 3 ] 1
A negative divisor gives the same result as a positive one. Mod[ 8, -3 ] 2
Test if a script variable is even. n := 12
r := Mod[n, 2] == 0
r = True

Mod[ list, n ]

If an argument is a list, the remainder is calculated for each element.

Example in out
The remainders when dividing by 3. Mod[ {10, 11, 12}, 3 ] {1, 2, 0}
Details
Invalid input Result
Mod[ 17, 0 ] Error: the second argument should be a non-zero natural number
Mod[ 17 ] Error: the number of arguments should be 2
Mod[ 17.5, 5 ], Mod[ x, 5 ] Left unevaluated: the arguments must be integers.

See also: CalcDivision, CalcDivisors, CalcGcd, EqualsEval