# Video: Identifying Common Factors of Numbers up to 100

Which number is a factor of 12 and a factor of 33?

02:24

### Video Transcript

Which number is a factor of 12 and a factor of 33?

Factors are numbers we can multiply together to get another number. Factors of 12 would be numbers that multiply together to equal 12. Factors of 33 would be numbers that multiply together to equal 33. Let’s find the factors of 12 and then the factors of 33 and see if any numbers on this list are found in both places.

What numbers multiply together to equal 12? To start, we know that one times 12 equals 12. So one and 12 are factors of 12. Two times six equals 12, both two and six are factors of 12. Finally, three times four equals 12. Three and four are factors of 12.

Let’s do the same thing with 33. One times 33 equals 33. 33 is not divisible by two. Three times 11 equals 33. And these are actually the only four factors of 33. 33 is not divisible by four, five, six, seven, eight, nine, or 10.

If we list out our factors of 12, they would look like this: one, two, three, four, six, and 12. Listing out the factors of 33, we get one, three, 11, and 33. We find one on both of these lists. We also find three on both of these lists. But our question is asking which of the given numbers is found as a factor of 12 and 33.

And the answer to that would be three. Three is a factor of 12 and a factor of 33.