Factors
Write all the factors for 21.
1 and 21, 3 and 7.
Write all the factors for 19.
1 and 19
List the first four multiples of 6.
6, 12, 18, 24
Name the first eight multiples of 5.
5: 5, 10, 15, 20, 25, 30, 35, 40
Is 2 prime or composite?
Prime
1 and 16, 2 and 8, 4 and 4.
Draw an area model to represent a factor pair for 18.
Answers will vary.
1 and 18, 2 and 9, 3 and 6.
Are all multiples of 4 multiples of 8? Hint: List the multiples of 4 and 8.
Yes because
4: 4, 8, 12, 16, 20, 24
8: 8, 16, 24
Both 4 and 5 are factors of 20. Is 20 a multiple of 4?
Yes because 4, 8, 12, 16, 20.
Is 14 prime or composite?
What are all the factor pairs for 12?
1 and 12, 2 and 6, 3 and 4.
1 and 10, 2 and 5
Maddie is giving out bags of school supplies. Pencils come in packages of 3. Pens come in packages of 4. How many packages of pens and pencils will Maddie need to put in each bag to have the same number of pens and pencils in each bag?
3: 3, 6, 9, 12
4: 4, 8, 12
Answer: 12 packages of pens and 12 packages of pencils
7, ____, 21, _____, _____, 42, _____
14, 28, 35, and 49
Is 17 prime or composite?
Prime
What are ALL the factor pairs of 144?
1 and 144, 2 and 72, 3 and 48, 4 and 36, 6 and 24, 8 and 18, 9 and 16, 12 and 12.
List ALL the factors of 54.
1 and 54, 2 and 27, 3 and 18, 6 and 9.
Which of these are multiples of 4?
8 14 16 18 56
8, 16, and 56
Which numbers are common multiples of 3 and 5? Hint: Make a Venn diagram!
5 9 15 45 60
15, 45, and 60
Is 56 prime or composite?
Composite
Is it true that a number cannot have more than four factor pairs? Hint: Choose a number that would have a lot of factor pairs.
No it is not true. For example, 100 has more than four factor pairs:
1 and 100, 2 and 50, 4 and 25, 5 and 20, 10 and 10.
A number has 6 as a factor. What other factors must the number have? Hint: Think of the factor pairs for 6.
1, 2, and 3. A number with 6 as a factor must also have all the factors of 6.
List the first ten multiples of 2 and 3. CIRCLE the first three common multiples.
2, 4, 6, 8, 10, 12, 14, 16, 18, and 20.
3, 6, 9, 12, 15, 18, 21, 24, 27, and 30.
Circled: 6, 12, and 18.
Can you find a common multiple of three numbers by multiplying the three numbers?
1: 1, 2, 3, 4, 5, 6
2: 2, 4, 6
3: 3, 6
The numbers 3, 5, and 7 are odd and prime. The number 9 is odd. Does that mean 9 is prime?
No, 9 is composite because 1 and 9, 3 and 3.