IsOdd Returns true if the given number is odd, false otherwise. Check whether a number is odd or even using the modulo (%) operator. Return true if the number is odd, false if the number is even. public static partial class _30s { public static bool IsOdd(int n) { return n % 2 != 0; } } _30s.IsOdd(3); // true _30s.IsOdd(4); // false