# Video: KS2-M18 • Paper 3 • Question 5

Tick the numbers that are common factors of both 12 and 18. [A] 2 [B] 3 [C] 6 [D] 9 [E] 12

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### Video Transcript

Tick the numbers that are common factors of both 12 and 18.

So the question is asking us to find common factors of 12 and 18. The factors of a number are the numbers we can multiply together to reach the number. So we can say that one and 12 are factors of 12 because if we multiply them together, they make 12. We can also multiply two and six together to make 12, and three and four.

Now, let’s find the factors of 18. One and 18 multiply to make 18. Two times nine makes 18. And three and six multiply to make 18.

Now, we just need to tick the numbers that are factors of both 12 and 18. Is two a common factor of 12 and 18? Yes, so we can tick number two. Is three a common factor of 12 and 18? Yes it is. So we can tick number three. How about number six? Yes, it’s a factor of both 12 and 18. Is number nine a factor of both 12 and 18? Nine is a factor of 18. But it isn’t a factor of 12. Is 12 a factor of both 12 and 18? It is a factor of 12, but not 18.

The numbers that are common factors of both 12 and 18 are two, three, and six.