Finding Factors
(KS2, Year 4)
Finding Factors
The factors of a number can be found.A Simple Example of How to Find Factors
Finding the factors of a number is easy. Find pairs of numbers that multiply to make that number.Question
What are the factors of the number 18?Step-by-Step:
1
1 and the number itself (18) are factors of 18.
1 × 18 = 18
Write 1 and 18 on the outside of a grid.
2
Divide 18 by 2. Does it divide exactly?
18 ÷ 2 = 9
Yes.
2 and the answer of the division (9) are factors of 18.
2 × 9 = 18
Write 2 and 9 in the grid, just inside the outside entries.
3
Divide 18 by 3. Does it divide exactly?
18 ÷ 3 = 6
Yes.
3 and the answer of the division (6) are factors of 18.
3 × 6 = 18
Write 3 and 6 in the grid, just inside the previous entries.
4
Divide 18 by 4. Does it divide exactly?
18 ÷ 4 = 4.5
No. The answer is not a whole number. 4 is not a factor.
5
Divide 18 by 5. Does it divide exactly?
18 ÷ 5 = 3.6
No. The answer is not a whole number. 5 is not a factor.
6
Divide 18 by 6.
We already know that 6 is a factor of 18, it is already in the grid.
We have found all the factors.
Answer:
The factors of 18 are 1, 2, 3, 6, 9 and 18.
This page was written by Stephen Clarke.
Worksheet
This test is printable and sendable
What Is a Factor?
A factor is a number which divides exactly into another number. The numbers that are multiplied together to make another number are factors.Negative Factors
Numbers can have negative factors. If 1 and 2 are factors of 2 (since 1 × 2 = 2), then −1 and −2 are also factors, since:
−1 × −2 = 2
For the tests on this lesson, just use the positive factors.
