Factors and Multiples
A factor is an integer (a whole number) that will divide exactly into another number. For example, 12 is a factor of 36 because 12 will divide into 36 exactly 3 times without any remainders. 9 is not a factor of 20 as it does not divide into 20 exactly, it leaves a remainder of 2.
A multiple of a number is any integer multiplied by the number. For example, 15 is a multiple of 5 because
Listing multiples of 5 gives 5, 10, 15, 20, 25 and so on
There are an infinite amount of multiples of any given number.