#### Transcript of Factors and Multiples

**Factors**

Factors are the numbers in a

multiplication sentence that are

being multiplied

8 X 7 = 56

Factors

When asked to find all of the factors of a certain number, I need to think of ALL of the possible multiplication sentences in which the target number is the product.

For example: "List ALL of the factors of 20" means to think of all of the combinations of factors in which 20 is the product

"Well...I know that 4 X 5 equals 20 so that means that 4 and 5 are factors of 20. Anything else...oh yeah 2 X 10 = 20 so 2 and 10 are also factors. 1 X 20 is also equal to 20 so...20 has a total of six possible factors -

1, 2, 4, 5, 10 and 20

Let's try another - All of the factors of 18: 1 and 18 of course (since 1 X 18 =18), 2 and 9 (since 2 X 9 = 18) , 3 and 6 (because 3 X 6 = 18) so all of the factors of 18 are 1, 2, 3, 6, 9, and 18.

What about 4? Isn't that a factor of 18?

Let's see

4 is NOT a factor of 18 because there is no multiplication sentence where I multiply 4 by a whole number and get 18

as a product.

**Multiples**

Multiples are the numbers you

say when you skip count by a number

5, 10, 15, 20, 25...etc.

multiples of 5

When asked to find multiples of a number, you will be given some more directions since you

cannot list ALL of the

multiples.

What are the multiples of 4 that are greater than 9 and less than 21?

I think: "what numbers would I say if I were counting by 4's that are between 9 and 21?"

4, 8,

12, 16, 20,

24, 28...

Here is another way to think about it

Is 42 a multiple of 5?

No...because if you count by 5's you will never say "42".

Full transcript