Prime or Composite
Is 3 a prime or composite number?
Prime
What is a factor?
Two numbers that are multiplied together to get a product.
Solve 5 x 5 using skip counting. Demonstrate on the board.
5 x 5 = 25
5 10 15 20 25
What is a multiple?
The product of two factors multiplied together.
What is a prime number?
A number that only has 2 factors, 1 and itself.
What are the factors of 8?
1 x 8 = 8
2 x 4 = 8
1, 2, 4, 8
Solve 6 x 4 using an array. Demonstrate on the board.
6 x 4 = 24
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What are the first 4 multiples of 4?
4 x 1 = 4
4 x 2 = 8
4 x 3 = 12
4 x 4 = 16
4, 8, 12, 16
Is 12 a prime or composite number?
Composite
What are the factors of 12?
1 x 12 = 12
2 x 6 = 12
3 x 4 = 12
1, 2, 3, 4, 6, 12
Solve 7 x 7 using repeated addition. Demonstrate on the board.
7 x 7 = 49
7 + 7 + 7 + 7 + 7 + 7 + 7 = 49
What are the first 5 multiples of 5?
5 x 1 = 5
5 x 2 = 10
5 x 3 = 15
5 x 4 = 20
5 x 5 = 25
5, 10, 15, 20, 25
Is 17 a prime or composite number?
Prime
What are the factors of 24?
1 x 24 = 24
2 x 12 = 24
3 x 8 = 24
4 x 6 = 24
1, 2, 3, 4, 6, 8, 12, 24
Solve 27 x 2 using doubles. Demonstrate on the board.
27
+27
____
54
What are the first 7 multiples of 3?
3 x 1 = 3
3 x 2 = 6
3 x 3 = 9
3 x 4 = 12
3 x 5 = 15
3 x 6 = 18
3 x 7 = 21
3, 6, 9, 12, 15, 18, 21
Is 77 a prime or composite number?
Composite
What are the factors of 100?
1 x 100 = 100
2 x 50 = 100
4 x 25 = 100
5 x 20 = 100
10 x 10 = 100
Johnny has 42 apples and he wants to share them with his 7 friends. How many apples will each friend get? Use equal groups to figure out the answer.
Each friend will get 6 apples.
What are the first 7 multiples of 8?
8 x 1 = 8
8 x 2 = 16
8 x 3 = 24
8 x 4 = 32
8 x 5 = 40
8 x 6 = 48
8 x 7 = 56
8, 16, 24, 32, 40, 48, 56