Prime & Composite Number
Is 22 prime or composite? Explain your reasoning.
22 is composite because it has more than 1 factor pair.
True or False: 12 is a multiple of 3. Explain.
True. 12 = 3 × 4.
Find all factor pairs of 12.
2: (1,12), (2,6), (3,4).
Jen has 40 pieces of candy. With 4 people, can the candy be divided equally? Explain.
Yes. 40 ÷ 4 = 10 each.
Is 23 prime or composite? Explain your reasoning.
23 is prime because it only has one factor pair
True or False: 18 is a factor of 9. Explain.
False. A factor of 9 must be less than or equal to 9;
Find all factor pairs of 45.
45: (1, 45), (3, 15), (5, 9)
Jen has 40 pieces of candy. With 3 people, can the candy be divided equally? Explain.
No. 40 ÷ 3 = 13 remainder 1, so not equal.
List three numbers between 1 and 100 that are prime and explain why each is prime.
2, 5, 7, 11, 13, 17, 23.......
They only have one factor pair.
True or False: 40 is a multiple of 4. Explain.
True. 40 = 4 × 10.
Find all factor pairs of 36 and say whether 36 is prime or composite.
36: (1,36),(2,18),(3,12),(4,9),(6,6) → composite.
With 4 people, what number of pieces of candy between 1 and 100 could be divided equally among the people? List at least five and explain your method.
Numbers divisible by 4 (between 1–100): 4,8,12,16,20,...
Is 13 prime or composite? Explain your reasoning
13 is prime because it only has one factor pair.
True or False: The only factor pair of 42 is 1 and 42. Explain.
False. 42 has factor pairs 1×42, 2 x 21, 3 X 14 and 6×7.
Find all the factor pairs of 16.
(1,16), (2, 8) (4, 4)
With 5 people, what number of pieces of candy between 1 and 100 could be divided equally among the people? List at least five and explain your method.
Numbers divisible by 5 (between 1–100):5, 10, 15, 20, 25, 30, 35, 40, 45, 50.......