# Find the GCF of 3 Numbers: Worksheets, Online Test and Calculators

Find the gcf of 3 numbers worksheets, solved worksheet problems or exercises with step-by-step work, formative assessment as online test, calculator and more learning resources to learn, practice, assess and master the basic math skills of divisors and factors.

## Find the GCF of 3 Numbers

Name
Date

1
Find the GCF of 12, 15 and 18
2
Find the GCF of 8, 10 and 12
3
Find the GCF of 9, 12 and 18
4
Find the GCF of 8, 12 and 16
5
Find the GCF of 12, 15 and 20
6
Find the GCF of 18, 24 and 36
7
Find the GCF of 6, 9 and 12
8
Find the GCF of 15, 20 and 25
9
Find the GCF of 6, 10 and 12
10
Find the GCF of 12, 16 and 18
11
Find the GCF of 20, 25 and 30
12
Find the GCF of 12, 14 and 16
13
Find the GCF of 24, 36 and 40
14
Find the GCF of 10, 12 and 14
15
Find the GCF of 30, 45 and 60
16
Find the GCF of 4, 10 and 12
17
Find the GCF of 12, 16 and 20
18
Find the GCF of 18, 24 and 32
19
Find the GCF of 10, 12 and 15
20
Find the GCF of 8, 12 and 18

Solved Worksheet Problems
1
Find the GCF of 12, 15 and 18
3 is the GCF of 12, 15 and 18
Factors of 12
 2 12 2 6 3 3 1
Factors of 15
 3 15 5 5 1
Factors of 18
 2 18 3 9 3 3 1

Factors of 12 = 2 x 2 x 3
Factors of 15 = 3 x 5
Factors of 18 = 2 x 3 x 3
Multiply all the common factors of 12, 15 and 18.
3 = 3
GCF(12, 15, 18) = 3
2
Find the GCF of 8, 10 and 12
2 is the GCF of 8, 10 and 12
Factors of 8
 2 8 2 4 2 2 1
Factors of 10
 2 10 5 5 1
Factors of 12
 2 12 2 6 3 3 1

Factors of 8 = 2 x 2 x 2
Factors of 10 = 2 x 5
Factors of 12 = 2 x 2 x 3
Multiply all the common factors of 8, 10 and 12.
2 = 2
GCF(8, 10, 12) = 2
3
Find the GCF of 9, 12 and 18
3 is the GCF of 9, 12 and 18
Factors of 9
 3 9 3 3 1
Factors of 12
 2 12 2 6 3 3 1
Factors of 18
 2 18 3 9 3 3 1

Factors of 9 = 3 x 3
Factors of 12 = 2 x 2 x 3
Factors of 18 = 2 x 3 x 3
Multiply all the common factors of 9, 12 and 18.
3 = 3
GCF(9, 12, 18) = 3
4
Find the GCF of 8, 12 and 16
4 is the GCF of 8, 12 and 16
Factors of 8
 2 8 2 4 2 2 1
Factors of 12
 2 12 2 6 3 3 1
Factors of 16
 2 16 2 8 2 4 2 2 1

Factors of 8 = 2 x 2 x 2
Factors of 12 = 2 x 2 x 3
Factors of 16 = 2 x 2 x 2 x 2
Multiply all the common factors of 8, 12 and 16.
2 x 2 = 4
GCF(8, 12, 16) = 4
5
Find the GCF of 12, 15 and 20
1 is the GCF of 12, 15 and 20
Factors of 12
 2 12 2 6 3 3 1
Factors of 15
 3 15 5 5 1
Factors of 20
 2 20 2 10 5 5 1

Factors of 12 = 2 x 2 x 3
Factors of 15 = 3 x 5
Factors of 20 = 2 x 2 x 5
Multiply all the common factors of 12, 15 and 20.
1 = 1
GCF(12, 15, 20) = 1
6
Find the GCF of 18, 24 and 36
6 is the GCF of 18, 24 and 36
Factors of 18
 2 18 3 9 3 3 1
Factors of 24
 2 24 2 12 2 6 3 3 1
Factors of 36
 2 36 2 18 3 9 3 3 1

Factors of 18 = 2 x 3 x 3
Factors of 24 = 2 x 2 x 2 x 3
Factors of 36 = 2 x 2 x 3 x 3
Multiply all the common factors of 18, 24 and 36.
2 x 3 = 6
GCF(18, 24, 36) = 6
7
Find the GCF of 6, 9 and 12
3 is the GCF of 6, 9 and 12
Factors of 6
 2 6 3 3 1
Factors of 9
 3 9 3 3 1
Factors of 12
 2 12 2 6 3 3 1

Factors of 6 = 2 x 3
Factors of 9 = 3 x 3
Factors of 12 = 2 x 2 x 3
Multiply all the common factors of 6, 9 and 12.
3 = 3
GCF(6, 9, 12) = 3
8
Find the GCF of 15, 20 and 25
5 is the GCF of 15, 20 and 25
Factors of 15
 3 15 5 5 1
Factors of 20
 2 20 2 10 5 5 1
Factors of 25
 5 25 5 5 1

Factors of 15 = 3 x 5
Factors of 20 = 2 x 2 x 5
Factors of 25 = 5 x 5
Multiply all the common factors of 15, 20 and 25.
5 = 5
GCF(15, 20, 25) = 5
9
Find the GCF of 6, 10 and 12
2 is the GCF of 6, 10 and 12
Factors of 6
 2 6 3 3 1
Factors of 10
 2 10 5 5 1
Factors of 12
 2 12 2 6 3 3 1

Factors of 6 = 2 x 3
Factors of 10 = 2 x 5
Factors of 12 = 2 x 2 x 3
Multiply all the common factors of 6, 10 and 12.
2 = 2
GCF(6, 10, 12) = 2
10
Find the GCF of 12, 16 and 18
2 is the GCF of 12, 16 and 18
Factors of 12
 2 12 2 6 3 3 1
Factors of 16
 2 16 2 8 2 4 2 2 1
Factors of 18
 2 18 3 9 3 3 1

Factors of 12 = 2 x 2 x 3
Factors of 16 = 2 x 2 x 2 x 2
Factors of 18 = 2 x 3 x 3
Multiply all the common factors of 12, 16 and 18.
2 = 2
GCF(12, 16, 18) = 2
11
Find the GCF of 20, 25 and 30
5 is the GCF of 20, 25 and 30
Factors of 20
 2 20 2 10 5 5 1
Factors of 25
 5 25 5 5 1
Factors of 30
 2 30 3 15 5 5 1

Factors of 20 = 2 x 2 x 5
Factors of 25 = 5 x 5
Factors of 30 = 2 x 3 x 5
Multiply all the common factors of 20, 25 and 30.
5 = 5
GCF(20, 25, 30) = 5
12
Find the GCF of 12, 14 and 16
2 is the GCF of 12, 14 and 16
Factors of 12
 2 12 2 6 3 3 1
Factors of 14
 2 14 7 7 1
Factors of 16
 2 16 2 8 2 4 2 2 1

Factors of 12 = 2 x 2 x 3
Factors of 14 = 2 x 7
Factors of 16 = 2 x 2 x 2 x 2
Multiply all the common factors of 12, 14 and 16.
2 = 2
GCF(12, 14, 16) = 2
13
Find the GCF of 24, 36 and 40
4 is the GCF of 24, 36 and 40
Factors of 24
 2 24 2 12 2 6 3 3 1
Factors of 36
 2 36 2 18 3 9 3 3 1
Factors of 40
 2 40 2 20 2 10 5 5 1

Factors of 24 = 2 x 2 x 2 x 3
Factors of 36 = 2 x 2 x 3 x 3
Factors of 40 = 2 x 2 x 2 x 5
Multiply all the common factors of 24, 36 and 40.
2 x 2 = 4
GCF(24, 36, 40) = 4
14
Find the GCF of 10, 12 and 14
2 is the GCF of 10, 12 and 14
Factors of 10
 2 10 5 5 1
Factors of 12
 2 12 2 6 3 3 1
Factors of 14
 2 14 7 7 1

Factors of 10 = 2 x 5
Factors of 12 = 2 x 2 x 3
Factors of 14 = 2 x 7
Multiply all the common factors of 10, 12 and 14.
2 = 2
GCF(10, 12, 14) = 2
15
Find the GCF of 30, 45 and 60
15 is the GCF of 30, 45 and 60
Factors of 30
 2 30 3 15 5 5 1
Factors of 45
 3 45 3 15 5 5 1
Factors of 60
 2 60 2 30 3 15 5 5 1

Factors of 30 = 2 x 3 x 5
Factors of 45 = 3 x 3 x 5
Factors of 60 = 2 x 2 x 3 x 5
Multiply all the common factors of 30, 45 and 60.
3 x 5 = 15
GCF(30, 45, 60) = 15
16
Find the GCF of 4, 10 and 12
2 is the GCF of 4, 10 and 12
Factors of 4
 2 4 2 2 1
Factors of 10
 2 10 5 5 1
Factors of 12
 2 12 2 6 3 3 1

Factors of 4 = 2 x 2
Factors of 10 = 2 x 5
Factors of 12 = 2 x 2 x 3
Multiply all the common factors of 4, 10 and 12.
2 = 2
GCF(4, 10, 12) = 2
17
Find the GCF of 12, 16 and 20
4 is the GCF of 12, 16 and 20
Factors of 12
 2 12 2 6 3 3 1
Factors of 16
 2 16 2 8 2 4 2 2 1
Factors of 20
 2 20 2 10 5 5 1

Factors of 12 = 2 x 2 x 3
Factors of 16 = 2 x 2 x 2 x 2
Factors of 20 = 2 x 2 x 5
Multiply all the common factors of 12, 16 and 20.
2 x 2 = 4
GCF(12, 16, 20) = 4
18
Find the GCF of 18, 24 and 32
2 is the GCF of 18, 24 and 32
Factors of 18
 2 18 3 9 3 3 1
Factors of 24
 2 24 2 12 2 6 3 3 1
Factors of 32
 2 32 2 16 2 8 2 4 2 2 1

Factors of 18 = 2 x 3 x 3
Factors of 24 = 2 x 2 x 2 x 3
Factors of 32 = 2 x 2 x 2 x 2 x 2
Multiply all the common factors of 18, 24 and 32.
2 = 2
GCF(18, 24, 32) = 2
19
Find the GCF of 10, 12 and 15
1 is the GCF of 10, 12 and 15
Factors of 10
 2 10 5 5 1
Factors of 12
 2 12 2 6 3 3 1
Factors of 15
 3 15 5 5 1

Factors of 10 = 2 x 5
Factors of 12 = 2 x 2 x 3
Factors of 15 = 3 x 5
Multiply all the common factors of 10, 12 and 15.
1 = 1
GCF(10, 12, 15) = 1
20
Find the GCF of 8, 12 and 18
2 is the GCF of 8, 12 and 18
Factors of 8
 2 8 2 4 2 2 1
Factors of 12
 2 12 2 6 3 3 1
Factors of 18
 2 18 3 9 3 3 1

Factors of 8 = 2 x 2 x 2
Factors of 12 = 2 x 2 x 3
Factors of 18 = 2 x 3 x 3
Multiply all the common factors of 8, 12 and 18.
2 = 2
GCF(8, 12, 18) = 2

## Worksheet: Find the GCF of 3 Numbers

Find the gcf of 3 numbers worksheet is the largest collection of practice problems and solved exercises which can be served as homework, classwork or assignment problems for the students to learn, practice, assess, iterate and master the skills of how to solve such divisors and factors problems in basic mathematics.