In math, the term distinct number is used to refer to a number in a set that is not equal to another number. For example, the set of numbers {1, 2} contains the two distinct numbers 1 and 2, which can be proven by evaluating different traits of each number.

The term distinct number may also be used in relation to functions. For example, the equation 4 = x^2 has two distinct values for x, as both -2^2 and 2^2 equal 4. A function that crosses the x-axis twice has two distinct numbers for the x-intercept. A quadratic function with complex numbers has two distinct number solutions, while a quadratic equation without complex numbers has only one distinct number for a solution.