Here's how to understand it:
* Divisor: A divisor is a number that divides another number completely, leaving no remainder.
* Non-divisor: A non-divisor is a number that, when divided into another number, leaves a remainder.
Examples:
* Divisor: 3 is a divisor of 12 because 12 / 3 = 4 (no remainder).
* Non-divisor: 5 is not a divisor of 12 because 12 / 5 = 2 with a remainder of 2.
Other examples of non-divisors:
* 7 is not a divisor of 10
* 2 is not a divisor of 3
* 10 is not a divisor of 5
Essentially, any number that does not divide evenly into another number is a non-divisor.