GCF and LCM Bellringer

What is the LCM (Least Common Multiple) of 4 and 10?

• 4

• 40

• 15

• 20

What is the GCF (Greatest Common Factor) of 12 and 6?

• 1

• 6

• 2

• 3

Find the LCM of 18 and 24

• 6
• 72
• 24
• 5

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

Find the missing number using the distributive property.
10 + 20  =  2(5 +  __)

• 2
• 4
• 5
• 10