Find Least Common Multiple of 42 and 35 using ladder method..

LCM( 42, 35 ) = 210

Step 1 : Place the numbers inside division bar:

Step 2 : Find a prime number which divides both numbers.

In this example we can divide by 7. If any number is not divisible by 7 write it down unchanged.

Step 4 : LCM is a product of numbers into L shape.

LCM = 7 · 6 · 5 = 210

This solution can be visualized using a Venn diagram.

The LCM is equal to the product of all the numbers on the diagram.