1. GCF and LCM The Ladder Method

3. Step 1: Write your numbers side by side inside a letter L »Ex.) 12 and 8 128

5. Step 2:Find the smallest number that will go into both numbers evenly and put it on the left of the L 2128

7. Step 3:Divide the number to the left into both numbers and put the answers underneath. Repeat steps 2 and 3 until you can no longer divide. 2128 64

9. Step 4:Repeat steps 2 and 3 until you can no longer divide. 2128 64 32 2

11. Step 5:Multiply all the numbers on the left of the L’s to find the GCF. 2 X 2 = 4 The GCF is 4 2128 64 32 2

13. Step 6:Multiply all the numbers on the left of the L’s and below the last L to find the LCM. 2 X 2 X 3 X 2 = 24 The LCM is 24 2128 64 32 2