Math Practice Problems - Greatest Common Factor

Greatest Common Factor - Sample Math Practice Problems

The math problems below can be generated by MathScore.com, a math practice program for schools and individual families. References to complexity and mode refer to the overall difficulty of the problems as they appear in the main program. In the main program, all problems are automatically graded and the difficulty adapts dynamically based on performance. Answers to these sample questions appear at the bottom of the page. This page does not grade your responses.

Learn more about our online math practice software.
See some of our other supported math practice problems.

Complexity=8

Find the greatest common factor of each pair of numbers.

1. 6, 4

2. 8, 5

Complexity=12

Find the greatest common factor of each pair of numbers.

1. 9, 6

2. 10, 6

Complexity=20

Find the greatest common factor of each pair of numbers.

1. 18, 6

2. 18, 13

Complexity=30

Find the greatest common factor of each pair of numbers.

1. 28, 16

2. 27, 18

Complexity=40

Find the greatest common factor of each pair of numbers.

1. 20, 24

2. 24, 30

Complexity=50

Find the greatest common factor of each pair of numbers.

1. 49, 35

2. 44, 48

Complexity=80

Find the greatest common factor of each pair of numbers.

1. 54, 45

2. 35, 63

Complexity=150

Find the greatest common factor of each pair of numbers.

1. 78, 138

2. 144, 99

Answers

Complexity=8

Find the greatest common factor of each pair of numbers.

#	Problem	Correct Answer	Your Answer
1	6, 4
Solution 6 - 4 = 2. Does 2 divide evenly into 4? Yes. Therefore 2 is the GCF. Factors of 6: 1, 2, 3, 6 Factors of 4: 1, 2, 4

#	Problem	Correct Answer	Your Answer
2	8, 5
Solution The factors of 5 are 1, 5. From greatest to least, check if each factor divides evenly into 8. 5 does not divide evenly into 8. 1 divides evenly into 8. Therefore, 1 is the GCF. Factors of 8: 1, 2, 4, 8 Factors of 5: 1, 5

Complexity=12

Find the greatest common factor of each pair of numbers.

#	Problem	Correct Answer	Your Answer
1	9, 6
Solution 9 - 6 = 3. Does 3 divide evenly into 6? Yes. Therefore 3 is the GCF. Factors of 9: 1, 3, 9 Factors of 6: 1, 2, 3, 6

#	Problem	Correct Answer	Your Answer
2	10, 6
Solution 10 - 6 = 4. GCF(10,6) = GCF(6, 4). The difference between 6 and 4 is 2. Does 2 divide evenly into 4? Yes. Therefore 2 is the GCF. Factors of 10: 1, 2, 5, 10 Factors of 6: 1, 2, 3, 6

Complexity=20

Find the greatest common factor of each pair of numbers.

Problem

Correct Answer

Your Answer

18, 6

Solution
6 divides evenly into 18. Therefore 6 must be the greatest common factor.

Factors of 18: 1, 2, 3, 6, 9, 18
Factors of 6: 1, 2, 3, 6

#	Problem	Correct Answer	Your Answer
2	18, 13
Solution The factors of 13 are 1, 13. From greatest to least, check if each factor divides evenly into 18. 13 does not divide evenly into 18. 1 divides evenly into 18. Therefore, 1 is the GCF. Factors of 18: 1, 2, 3, 6, 9, 18 Factors of 13: 1, 13

Complexity=30

Find the greatest common factor of each pair of numbers.

#	Problem	Correct Answer	Your Answer
1	28, 16
Solution 28 - 16 = 12. GCF(28,16) = GCF(16, 12). The difference between 16 and 12 is 4. Does 4 divide evenly into 12? Yes. Therefore 4 is the GCF. Factors of 28: 1, 2, 4, 7, 14, 28 Factors of 16: 1, 2, 4, 8, 16

#	Problem	Correct Answer	Your Answer
2	27, 18
Solution 27 - 18 = 9. Does 9 divide evenly into 18? Yes. Therefore 9 is the GCF. Factors of 27: 1, 3, 9, 27 Factors of 18: 1, 2, 3, 6, 9, 18

Complexity=40

Find the greatest common factor of each pair of numbers.

#	Problem	Correct Answer	Your Answer
1	20, 24
Solution 24 - 20 = 4. Does 4 divide evenly into 20? Yes. Therefore 4 is the GCF. Factors of 20: 1, 2, 4, 5, 10, 20 Factors of 24: 1, 2, 3, 4, 6, 8, 12, 24

#	Problem	Correct Answer	Your Answer
2	24, 30
Solution 30 - 24 = 6. Does 6 divide evenly into 24? Yes. Therefore 6 is the GCF. Factors of 24: 1, 2, 3, 4, 6, 8, 12, 24 Factors of 30: 1, 2, 3, 5, 6, 10, 15, 30

Complexity=50

Find the greatest common factor of each pair of numbers.

#	Problem	Correct Answer	Your Answer
1	49, 35
Solution The factors of 35 are 1, 5, 7, 35. From greatest to least, check if each factor divides evenly into 49. 35 does not divide evenly into 49. 7 divides evenly into 49. Therefore, 7 is the GCF. Factors of 49: 1, 7, 49 Factors of 35: 1, 5, 7, 35

#	Problem	Correct Answer	Your Answer
2	44, 48
Solution 48 - 44 = 4. Does 4 divide evenly into 44? Yes. Therefore 4 is the GCF. Factors of 44: 1, 2, 4, 11, 22, 44 Factors of 48: 1, 2, 3, 4, 6, 8, 12, 16, 24, 48

Complexity=80

Find the greatest common factor of each pair of numbers.

#	Problem	Correct Answer	Your Answer
1	54, 45
Solution 54 - 45 = 9. Does 9 divide evenly into 45? Yes. Therefore 9 is the GCF. Factors of 54: 1, 2, 3, 6, 9, 18, 27, 54 Factors of 45: 1, 3, 5, 9, 15, 45

#	Problem	Correct Answer	Your Answer
2	35, 63
Solution 63 - 35 = 28. GCF(63,35) = GCF(35, 28). The difference between 35 and 28 is 7. Does 7 divide evenly into 28? Yes. Therefore 7 is the GCF. Factors of 35: 1, 5, 7, 35 Factors of 63: 1, 3, 7, 9, 21, 63

Complexity=150

Find the greatest common factor of each pair of numbers.

#	Problem	Correct Answer	Your Answer
1	78, 138
Solution The factors of 78 are 1, 2, 3, 6, 13, 26, 39, 78. From greatest to least, check if each factor divides evenly into 138. 78 does not divide evenly into 138. 39 does not divide evenly into 138. 26 does not divide evenly into 138. 13 does not divide evenly into 138. 6 divides evenly into 138. Therefore, 6 is the GCF. Factors of 78: 1, 2, 3, 6, 13, 26, 39, 78 Factors of 138: 1, 2, 3, 6, 23, 46, 69, 138

#	Problem	Correct Answer	Your Answer
2	144, 99
Solution The factors of 99 are 1, 3, 9, 11, 33, 99. From greatest to least, check if each factor divides evenly into 144. 99 does not divide evenly into 144. 33 does not divide evenly into 144. 11 does not divide evenly into 144. 9 divides evenly into 144. Therefore, 9 is the GCF. Factors of 144: 1, 2, 3, 4, 6, 8, 9, 12, 16, 18, 24, 36, 48, 72, 144 Factors of 99: 1, 3, 9, 11, 33, 99

Learn more about our online math practice software.

"MathScore works."
- John Cradler, Educational Technology Expert