Factors
List the factors of 15.
1 x 15
3 x 5
(1,15,3,5)
Is 24 a multiple of 3?
How can you tell?
Yes, because 8 x 3 = 24.
Is 49 prime or composite?
How can you tell?
Composite.
1 x 49 and 7x7
List the factors of 30.
1 x 30
2 x 15
3 x 10
5 x 6
(1,2,3,5,6,10,15,30)
Is 36 a multiple of 4?
How can you tell?
Yes, because 9 x 4 = 36.
Is 43 prime or composite?
How can you tell?
Prime.
It only has two factors: 1 x 43.
List the factors of 42.
1 x 42
2 x 21
3 x 14
6 x 7
(1,2,3,6,7,14,21,42)
Is 100 a multiple of 6?
How can you tell?
No, because nothing x 6 is 100.
Is 99 prime or composite?
How can you tell?
Composite.
1 x 99
9 x 11
33 x 3
List the factors of 80.
1 x 80. 2 x 40. 4 x 20. 5 x 16
8 x 10
(1,2,4,5,8,10,16, 20,40,80)
Is 45 a multiple of 15?
How can you tell?
Yes, because 15 x 3 = 45.
Is 109 prime or composite?
How can you tell?
Prime. It only has two factors.
1 x 109
List the factors of 200.
1 x 200. (1,2,4,5,10,20,40,50,100,200)
2 x 100
4 x 50
5 x 40
10 x 20
Is 108 a multiple of 3?
How can you tell?
Yes, because 3 x 36 is 108.
I divided 108 by 3 to check my answer.
Is 321 prime or composite?
How can you tell?
Composite.
It has more than 2 factors.
1 x 321
3 x 107 (I divided by 3 to figure it out!)