Factors and Multiples

What is the HCF of 18 and 24?

• 3

• 6

• 8

• 9

What is the least common multiple (LCM) of 6 and 8?

• 6
• 8
• 48
• 24

Two neon signs are turned on at the same time.  Both signs blink as they are turned on.  One sign blinks every 9 seconds.  The other sign blinks every 15 seconds.  In how many seconds will they blink together?

• 30
• 45
• 50
• 90

List the first 5 multiples of 20

• 1, 2, 4, 5, 10

• 1, 20, 2, 10, 4, 5

• 20, 40, 60, 80, 100

• 20, 25, 30, 35, 40

List the factors of 12.

• 1, 2, 3, 4, 6, 12

• 12, 24, 36, 48, 60...

• 1, 12, 24, 4, 6

Which is a factor of 15?

• 2

• 3

• 4

• 6

What is the HCF of 8 and 10?

• 1
• 3
• 4
• 2

Which is a multiple of 4?

• 9

• 6

• 8

• 15