Name
Grade
School

Date
Questions20
Score

1

Find the LCM of 8 and 12

2

Find the LCM of 9 and 12

3

Find the LCM of 6 and 8

4

Find the LCM of 8 and 10

5

Find the LCM of 12 and 15

6

Find the LCM of 12 and 18

7

Find the LCM of 12 and 16

8

Find the LCM of 6 and 9

9

Find the LCM of 24 and 36

10

Find the LCM of 9 and 15

11

Find the LCM of 8 and 9

12

Find the LCM of 4 and 5

13

Find the LCM of 18 and 24

14

Find the LCM of 10 and 15

15

Find the LCM of 16 and 24

16

Find the LCM of 4 and 10

17

Find the LCM of 10 and 12

18

Find the LCM of 4 and 6

19

Find the LCM of 15 and 25

20

Find the LCM of 5 and 6

Answers Key

1

Find the LCM of 8 and 12

24 is the LCM of 8 and 12

Factors of 8

2 | 8 |

2 | 4 |

2 | 2 |

1 |

Factors of 12

2 | 12 |

2 | 6 |

3 | 3 |

1 |

Factors of 8 = 2 x 2 x 2

Factors of 12 = 2 x 2 x 3

Multiply all the common and uncommon factors of 8 and 12.

2 x 2 x 2 x 3 = 24

LCM(8, 12) = 24

2

Find the LCM of 9 and 12

36 is the LCM of 9 and 12

Factors of 9

3 | 9 |

3 | 3 |

1 |

Factors of 12

2 | 12 |

2 | 6 |

3 | 3 |

1 |

Factors of 9 = 3 x 3

Factors of 12 = 2 x 2 x 3

Multiply all the common and uncommon factors of 9 and 12.

2 x 2 x 3 x 3 = 36

LCM(9, 12) = 36

3

Find the LCM of 6 and 8

24 is the LCM of 6 and 8

Factors of 6

2 | 6 |

3 | 3 |

1 |

Factors of 8

2 | 8 |

2 | 4 |

2 | 2 |

1 |

Factors of 6 = 2 x 3

Factors of 8 = 2 x 2 x 2

Multiply all the common and uncommon factors of 6 and 8.

2 x 2 x 2 x 3 = 24

LCM(6, 8) = 24

4

Find the LCM of 8 and 10

40 is the LCM of 8 and 10

Factors of 8

2 | 8 |

2 | 4 |

2 | 2 |

1 |

Factors of 10

2 | 10 |

5 | 5 |

1 |

Factors of 8 = 2 x 2 x 2

Factors of 10 = 2 x 5

Multiply all the common and uncommon factors of 8 and 10.

2 x 2 x 2 x 5 = 40

LCM(8, 10) = 40

5

Find the LCM of 12 and 15

60 is the LCM of 12 and 15

Factors of 12

2 | 12 |

2 | 6 |

3 | 3 |

1 |

Factors of 15

3 | 15 |

5 | 5 |

1 |

Factors of 12 = 2 x 2 x 3

Factors of 15 = 3 x 5

Multiply all the common and uncommon factors of 12 and 15.

2 x 2 x 3 x 5 = 60

LCM(12, 15) = 60

6

Find the LCM of 12 and 18

36 is the LCM of 12 and 18

Factors of 12

2 | 12 |

2 | 6 |

3 | 3 |

1 |

Factors of 18

2 | 18 |

3 | 9 |

3 | 3 |

1 |

Factors of 12 = 2 x 2 x 3

Factors of 18 = 2 x 3 x 3

Multiply all the common and uncommon factors of 12 and 18.

2 x 2 x 3 x 3 = 36

LCM(12, 18) = 36

7

Find the LCM of 12 and 16

48 is the LCM of 12 and 16

Factors of 12

2 | 12 |

2 | 6 |

3 | 3 |

1 |

Factors of 16

2 | 16 |

2 | 8 |

2 | 4 |

2 | 2 |

1 |

Factors of 12 = 2 x 2 x 3

Factors of 16 = 2 x 2 x 2 x 2

Multiply all the common and uncommon factors of 12 and 16.

2 x 2 x 2 x 2 x 3 = 48

LCM(12, 16) = 48

8

Find the LCM of 6 and 9

18 is the LCM of 6 and 9

Factors of 6

2 | 6 |

3 | 3 |

1 |

Factors of 9

3 | 9 |

3 | 3 |

1 |

Factors of 6 = 2 x 3

Factors of 9 = 3 x 3

Multiply all the common and uncommon factors of 6 and 9.

2 x 3 x 3 = 18

LCM(6, 9) = 18

9

Find the LCM of 24 and 36

72 is the LCM of 24 and 36

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 24 = 2 x 2 x 2 x 3

Factors of 36 = 2 x 2 x 3 x 3

Multiply all the common and uncommon factors of 24 and 36.

2 x 2 x 2 x 3 x 3 = 72

LCM(24, 36) = 72

10

Find the LCM of 9 and 15

45 is the LCM of 9 and 15

Factors of 9

3 | 9 |

3 | 3 |

1 |

Factors of 15

3 | 15 |

5 | 5 |

1 |

Factors of 9 = 3 x 3

Factors of 15 = 3 x 5

Multiply all the common and uncommon factors of 9 and 15.

3 x 3 x 5 = 45

LCM(9, 15) = 45

11

Find the LCM of 8 and 9

72 is the LCM of 8 and 9

Factors of 8

2 | 8 |

2 | 4 |

2 | 2 |

1 |

Factors of 9

3 | 9 |

3 | 3 |

1 |

Factors of 8 = 2 x 2 x 2

Factors of 9 = 3 x 3

Multiply all the common and uncommon factors of 8 and 9.

2 x 2 x 2 x 3 x 3 = 72

LCM(8, 9) = 72

12

Find the LCM of 4 and 5

20 is the LCM of 4 and 5

Factors of 4

2 | 4 |

2 | 2 |

1 |

Factors of 5

5 | 5 |

1 |

Factors of 4 = 2 x 2

Factors of 5 = 5

Multiply all the common and uncommon factors of 4 and 5.

2 x 2 x 5 = 20

LCM(4, 5) = 20

13

Find the LCM of 18 and 24

72 is the LCM of 18 and 24

Factors of 18

2 | 18 |

3 | 9 |

3 | 3 |

1 |

Factors of 24

2 | 24 |

2 | 12 |

2 | 6 |

3 | 3 |

1 |

Factors of 18 = 2 x 3 x 3

Factors of 24 = 2 x 2 x 2 x 3

Multiply all the common and uncommon factors of 18 and 24.

2 x 2 x 2 x 3 x 3 = 72

LCM(18, 24) = 72

14

Find the LCM of 10 and 15

30 is the LCM of 10 and 15

Factors of 10

2 | 10 |

5 | 5 |

1 |

Factors of 15

3 | 15 |

5 | 5 |

1 |

Factors of 10 = 2 x 5

Factors of 15 = 3 x 5

Multiply all the common and uncommon factors of 10 and 15.

2 x 3 x 5 = 30

LCM(10, 15) = 30

15

Find the LCM of 16 and 24

48 is the LCM of 16 and 24

Factors of 16

2 | 16 |

2 | 8 |

2 | 4 |

2 | 2 |

1 |

Factors of 24

2 | 24 |

2 | 12 |

2 | 6 |

3 | 3 |

1 |

Factors of 16 = 2 x 2 x 2 x 2

Factors of 24 = 2 x 2 x 2 x 3

Multiply all the common and uncommon factors of 16 and 24.

2 x 2 x 2 x 2 x 3 = 48

LCM(16, 24) = 48

16

Find the LCM of 4 and 10

20 is the LCM of 4 and 10

Factors of 4

2 | 4 |

2 | 2 |

1 |

Factors of 10

2 | 10 |

5 | 5 |

1 |

Factors of 4 = 2 x 2

Factors of 10 = 2 x 5

Multiply all the common and uncommon factors of 4 and 10.

2 x 2 x 5 = 20

LCM(4, 10) = 20

17

Find the LCM of 10 and 12

60 is the LCM of 10 and 12

Factors of 10

2 | 10 |

5 | 5 |

1 |

Factors of 12

2 | 12 |

2 | 6 |

3 | 3 |

1 |

Factors of 10 = 2 x 5

Factors of 12 = 2 x 2 x 3

Multiply all the common and uncommon factors of 10 and 12.

2 x 2 x 3 x 5 = 60

LCM(10, 12) = 60

18

Find the LCM of 4 and 6

12 is the LCM of 4 and 6

Factors of 4

2 | 4 |

2 | 2 |

1 |

Factors of 6

2 | 6 |

3 | 3 |

1 |

Factors of 4 = 2 x 2

Factors of 6 = 2 x 3

Multiply all the common and uncommon factors of 4 and 6.

2 x 2 x 3 = 12

LCM(4, 6) = 12

19

Find the LCM of 15 and 25

75 is the LCM of 15 and 25

Factors of 15

3 | 15 |

5 | 5 |

1 |

Factors of 25

5 | 25 |

5 | 5 |

1 |

Factors of 15 = 3 x 5

Factors of 25 = 5 x 5

Multiply all the common and uncommon factors of 15 and 25.

3 x 5 x 5 = 75

LCM(15, 25) = 75

20

Find the LCM of 5 and 6

30 is the LCM of 5 and 6

Factors of 5

5 | 5 |

1 |

Factors of 6

2 | 6 |

3 | 3 |

1 |

Factors of 5 = 5

Factors of 6 = 2 x 3

Multiply all the common and uncommon factors of 5 and 6.

2 x 3 x 5 = 30

LCM(5, 6) = 30