Find Least Common Multiple of 4, 6, 8 and 10 using ladder method..

LCM( 4, 6, 8, 10 ) = 120

Step 1 : Place the numbers inside division bar:

Step 2 : Find a prime number which can divide at least two of your numbers.

In this example we can divide by 2. If any number is not divisible by 2 write it down unchanged.

Step 3 : Repeat Step 2 until you can no longer divide.

Since there are no primes that divides at least two of given numbers, we conclude that the LCM is a product of starting numbers.

LCM = 4 · 6 · 8 · 10 = 120