- The Ladder Method is used to find the Greatest Common Factor (GCF) and Least Common Multiple (LCM) of two numbers, here 24 and 36.
- First, divide both numbers by a common prime factor. The image shows dividing by 4 (which is not prime, but the method still works if you use composite factors as long as they are common). This gives 6 and 9.
- Next, divide the resulting numbers by another common factor, which is 3. This gives 2 and 3.
- Since 2 and 3 have no common factors other than 1, the process stops.
- To find the GCF, multiply all the numbers on the left side of the ladder: 4 × 3 = 12.
- To find the LCM, multiply all the numbers on the left side of the ladder and the numbers at the bottom: 4 × 3 × 2 × 3 = 72.
Parent Tip: Review the logic above to help your child master the concept of gcf and lcm worksheet.
