Factors

A factor is a whole number that divides exactly into a whole number, leaving no remainder. For example, 3 is a factor of 9 because when you divide 9 by 3 (9 ÷ 3 = 3 remainder 0), it divides exactly into itself leaving no remainder. So 3 is one of the factors of 9.

• In simple terms, a number can be made by multiplying two or more numbers. The numbers that are multiplied together to make that number are called factors of the final number. In the following example, 2 and 3 are the factors of 6.

• Some numbers will have more than 2 factors. For example, consider 12

                1 x 12 = 12

                2 x 6 = 12

                3 x 4 =12

                Here the factors of 12 are 1, 2, 3, 4, 6 and 12.

• When you multiply any number by one, it will produce the same number. So number 1 is the factor of any given number. 

                For example, 1 x 15 = 15

                1 x 6 = 6

• Since all numbers can be divided by the number itself to produce 1, usually we ignore 1 and the number itself as the useful factors of a number.

                For example, 15/15 = 1 and 4/4 = 1

Facts about Factors

• Any even number will have factor 2.
• Any number ending in 5 will have factor 5.
• Any number above 0 that ends with 0 (such as 10, 20, 100…) will have factors two and five