Remember: The greatest common factor is the biggest number that goes into both. The least common multiple is the first number both lists reach.
Greatest common factor, least common multiple
1
A teacher has 36 pencils and 54 erasers. She makes the most identical kits, with nothing left over. How many kits?
2
How many erasers go in one kit?
3
The lists show every factor of 42 and of 56. What is the greatest common factor of 42 and 56?
4
Which pair of numbers has a greatest common factor of 1?
8 and 129 and 166 and 15
5
The lists show the first multiples of 12 and of 18. What is the least common multiple of 12 and 18?
6
What is the least common multiple of 8 and 14?
7
Bus A leaves every 10 minutes and bus B every 15 minutes. They both leave at 8:00. When do they next leave together?
8:258:309:00
8
54 + 90 = × (3 + 5)
9
Because 7 goes into 28 and into 35, 28 + 35 = 7 × (4 + 5).
TrueFalse
10
The least common multiple of 6 and 15 is 90.
TrueFalse
11
Join each to its answer.
1greatest common factor of 20 and 50
2least common multiple of 20 and 50
3greatest common factor of 18 and 24
4least common multiple of 18 and 24
A10
B6
C72
D100
12
Circle every common multiple of 4 and 6 that is less than 40.
1812302436
13
Write how you know the greatest common factor of 15 and 40 is 5 and not 10.
Scan the code at the top to mark this sheet on screenTake a photo of your answers or type them. It is marked for you automatically, and your score is kept.