Math-Unit 1: Multiplication

A factor is a number multiplied by another number to get a product (answer). Example: in the equation 5 x 2 = 10, 5 and 2 are factors of 10.

Multiples are the numbers you say when you count by a number. Example: the multiples of 2 are 2, 4, 6, 8, 10, 12,...

A prime number is a number with only two factors, 1 and itself.

A square number is a number that you get when you multiply two of the same number together. Example. multiply 5 x 5 to get the square number 25. The first few square numbers are 1, 4, 9, 16, and 25.

A composite number is a number that is not prime. A composite number has more than two factors. Example: 12 is composite because its factors are 1, 2, 3, 4, 6, and 12 since 1 x 12 = 12, 2 x 6 = 6, and 3 x 4 = 12. These are all of the multiplication combinations for 12.

1, 2, 5, 10

Here's why:
because 1 x 10 = 1 and 2 x 5 = 10

1, 2, 3, 4, 6, 9, 12, 18, and 36

Here's why:
because 1 x 36 = 36, 2 x 18 = 36, 3 x 12 = 36, 4 x 9 = 36, and 6 x 6 = 36. (36 is a square number.)

3, 6, 9, 12, 15

6, 12, 18, 24, 36

2, 3, 5, 7, 11

Here's why:
because the only way to multiply to get each number is that number times 1.
What comes next?

Composite because 14 has more factors than 1 and 14. Another combination for 14 is 2 x 7. So, the factors of 14 are 1, 2, 7, and 14.

Prime because the only way to get 17 is 1 x 17.

Prime because only 1 x 19 = 19.

Composite because the factors of 9 are: 1, 3, and 9 (1 x 9 = 9 and 3 x 3 = 9. Nine is also a square number.

Yes, because 49 is the product of 7 x 7. (Two of the same number multiplied together result in a square number.)

540

320

4,800

42,000

27 divided by 9 = 3, and

27 divided by 3 = 9