GCF/LCM Worksheet
1 a.  Find the LCM of these numbers:
12,  45
 
 
1 b.  Find the GCF of these numbers:
75,  30
 
 
2 a.  Find the LCM of these numbers:
42,  39
 
 
2 b.  Find the GCF of these numbers:
7,  70
 
 
3 a.  Find the GCF of these numbers:
100,  38
 
 
3 b.  Find the GCF of these numbers:
30,  48
 
 
4 a.  Find the LCM of these numbers:
62,  71
 
 
4 b.  Find the LCM of these numbers:
12,  79
 
 
5 a.  Find the LCM of these numbers:
79,  46
 
 
5 b.  Find the GCF of these numbers:
39,  26
 
 
6 a.  Find the LCM of these numbers:
39,  18
 
 
6 b.  Find the LCM of these numbers:
79,  52
 
 
7 a.  Find the GCF of these numbers:
20,  100
 
 
7 b.  Find the GCF of these numbers:
28,  84
 
 
8 a.  Find the GCF of these numbers:
80,  32
 
 
8 b.  Find the LCM of these numbers:
13,  4
 
 
9 a.  Find the GCF of these numbers:
36,  45
 
 
9 b.  Find the LCM of these numbers:
70,  30
 
 
10 a.  Find the LCM of these numbers:
11,  91
 
 
10 b.  Find the GCF of these numbers:
13,  26
 
 
Page 2

Answer Key

1 a.  180

 
1 b.  15

 
2 a.  546

 
2 b.  7

 
3 a.  2

 
3 b.  6

 
4 a.  4402

 
4 b.  948

 
5 a.  3634

 
5 b.  13

 
6 a.  234

 
6 b.  4108

 
7 a.  20

 
7 b.  28

 
8 a.  16

 
8 b.  52

 
9 a.  9

 
9 b.  210

 
10 a.  1001

 
10 b.  13

 

Copying permission: You are free to copy this worksheet to any number of students for their mathematics work. Do not distribute on websites, books, or any such material without permission. Copyright www.HomeschoolMath.net