Prime and Composite
Is 13 a prime or composite number? Explain or show your reasoning.
Prime because the only factor pair is 1 x 13
Find all factor pairs for 12
1 x 12, 2 x 6 and 3 x 4
16 is a multiple of 8. True or false?
True
Mrs. Lechner is playing a card game. The number of players always changes but the number of cards stay the same. If she had 4 players, could she play with 40 cards? Explain.
Yes because 4 x 10 = 40. Each player would get 10 cards.
Is 15 a prime or composite number? Explain or show your reasoning.
Composite because there is more than one factor pair. 1 x 15, and 3 x 5
Find all factor pairs for 25
1 x 25, and 5 x 5
17 is a multiple of 7. True or false?
False
Ms. Morgan is playing a game. She has 50 cards. Each player needs to have an equal amount of cards. Could she play with 3 players? Explain.
No. 50 does not divide equally into 3 groups.
No, you cannot skip count by 3s to get to 50.
Is 27 a prime or composite number? Explain or show your reasoning.
Composite because there are more than one factor pairs. 1 x 27 and 3 x 9
Find all factor pairs for 48
1 x 48, 2 x 24, 3 x 16, 4 x 12, 6 x 8
5 is a multiple of 20.
False
Mrs. McCarty is playing a card game. The cards can be divided equally between 2 players, 4 players and 6 players. How many cards could there be? Explain or show your reasoning.
2, 4, 6, 8, 10,12,14,16,18,20,22,24
4, 8, 12, 16, 20, 24
6, 12, 18, 24
Is 36 a prime or composite number? Explain or show your reasoning.
Composite because the factor pairs are 1 x 36, 2 x 18, 3 x 12 and 4 x 9.
Find all the factor pairs for 49
1 x 49 and 7 x 7
30 is a multiple of 3
true
Dr. G has some m&ms. She can divide them equally into 3, 5, and 6 people. How many m&ms could she have?
30. You can skip count by 3, 5 and 6 to find a common multiple.
3,6,9,12,15,18,21,24,27,30
5,10,15,20,25,30
6,12,18,24,30
Carlos says that 39 is a prime number because it is odd and all odd numbers are prime. Wanda says that 39 is prime because the only factor pairs are 1 x 39. Who do you agree with?
Wanda because 39 only has one factor pair which is 1 x 39. Carlos is wrong because not all odd numbers are prime.
15 is a factor of 30. True or false?
True, 2 x 15 is 30
8, 12, 16, 20 are all multiples of what?
A. 8s
B. 4s
C. 12s
D. 6s
B. 4s
Mrs. Sample has some baby yoda figurines. She can split them between 4, 6, and 8 people. How many baby yoda figurines could she have?
24 or 48. If you skip count by 4, 6 and 8 you will find a few common multiples.
4,8,12,16,20,24,28, 32,36,40,44,48
6,12,18,24,30,36,42,48
8,16,24,32,40,48