# Lesson Worksheet: Common Factors Mathematics • 4th Grade

In this worksheet, we will practice finding the common factors of two or three whole numbers by listing their factors.

Q1:

Which number is a factor of 12 and a factor of 33? Q2:

Which of the following numbers is not a common factor of 60 and 90?

• A3
• B15
• C13
• D10
• E2

Q3:

Find all the factors of the numbers 15 and 87.

• A
• B
• C
• D

Q4:

Determine the common factors of the following set of numbers: 28, 72, 84.

• A1, 2, 4
• B1, 2, 4, 6
• C2, 4
• D1, 2, 4, 7, 14, 28
• E1, 2, 3, 4, 6, 12

Q5:

The diagram shows the three pairs of factors of the number 18. The first pair, 1 and 18, is represented in A, showing 18 as or .

What pairs of factors do B and C represent? • AB: 2 and 9, C:3 and 9
• BB: 2 and 9, C: 3 and 6
• CB:3 and 6, C:3 and 18
• DB:3 and 9, C:2 and 6
• EB: 2 and 18, C: 3 and 18

The diagrams show the pairs of factors of 12 as in the previous question (left) and also using the area model of multiplication (right). What pairs of factors of 12 do diagrams A, B, and C represent? • AA: 2 and 6, B: 4 and 4, C :3 and 3
• BA: 2 and 10, B: 2 and 3, C: 3 and 4
• CA: 1 and 12, B: 2 and 6, C: 3 and 4
• DA: 2 and 10, B: 2 and 6, C: 6 and 6
• EA: 1 and 12, B: 2 and 3, C: 6 and 4

What are all the common factors of 12 and 18?

• A1, 2, 3, and 4
• B1, 2, 3, and 6
• C1, 2, and 3
• D2, 3, and 6
• E1, 2, 3, 4 and 5

What is the greatest common factor of 12 and 18?

A gardener wants to plant 18 orange and 12 blue flowers in rows with the same numbers of orange and blue flowers in each row. She thinks there are four possibilities to do so. Is she right?

• AYes
• BNo

How many rows would she get in each of the four possibilities?

• A1, 3, 4, or 5
• B2, 3, 4, or 5
• C1, 2, 3, or 4
• D2, 3, 4, or 6
• E1, 2, 3, or 6

The diagram represents the four possibilities using the four common factors of 18 and 12. Which common factor leads to largest number of rows? Q6:

Which of the following numbers is not a common factor of 36 and 90?

• A6
• B3
• C5
• D2
• E9

Q7:

Which of the following numbers is not a common factor of 84 and 96?

• A4
• B6
• C7
• D3
• E2

Q8:

Emma claims that any two numbers have the common factor 1. Is she right?

• ANo
• BYes

Q9:

Noah claims that zero is a factor of only one number, which is the zero itself. Is this true?

• AYes
• BNo

Q10:

Which of the following numbers is a common factor of 36, 24, and 12?

• A6
• B12
• C3
• D4
• E8

Q11:

Which of the following numbers have the common factors 1, 3, and 5?

• A
• B
• C
• D
• E

Q12:

Which of the following numbers have the common factors 1, 3, and 5?

• A
• B
• C
• D
• E

Q13:

Are all factors of 9 also factors of 18?

• ANo
• BYes

Q14:

Find three common factors between 60, 80, and 100.

• A4, 11, 8
• B12, 7, 4
• C10, 5, 2
• D12, 8, 0

Q15:

Find the common factors of the numbers 27 and 90.

• A3, 9
• B1, 2, 3, 6, 9, 18
• C1, 3, 9
• D1, 2, 3, 5, 6, 9, 10, 15, 18, 27, 30, 45, 90

Q16:

True or False: There are no common factors between 17 and 59.

• AFalse
• BTrue

Q17:

Which of these pairs of numbers has a common factor of 2?

• A24 and 28
• B28 and 27
• C24 and 21
• D24 and 27
• E21 and 27

Q18:

Which of these is a common factor of the numbers 12, 48, and 52?

• A24
• B8
• C12
• D6
• E4