### Find the lowest common multiple for 15 and 20.

# Lowest Common Multiple Calculator

Step 1.Write out a list of multiples for each number.

Step 3. The number found on each list will be your LCM or Lowest Common Multiple in this example it is 60

Step 2. Cross out numbers that are not found on each list.

## Common multiple calculator

**Find the lowest common multiple ( lcm ) of 5 and 6**

Prime factorization of** 5 =** 10 15 20 25 **30**

Prime factorization of** 6 =** 12 18 24 **30**

**Find the lowest common multiple ( lcm ) of 4 ,12 , and 30**

Prime factorization of **4=** 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56*,* **60**

Prime factorization of **12= **24, 36, 48 ,**60**

Prime factorization **30**= **60**

## How do you find the LCM of polynomials?

Follow these steps to find the LCM of polynomials

1. Factor

2. Write each factor,not duplicating the "common" ones

3. Multiply these factors together

**For example: Find the LCM of 4x^2 and 10xy**

**Step 1.** Factor 4x^2 = 2*2 x*x 10xy = 2*5 x*y

**Step 2.** Write down each factor and not duplicate common ones

2*2*5*x*x*y

**Step 3**. Multiply these together 20x^2y

These problems are difficult to explain verbally. I feel watching someone work several examples will help understanding.

**Common Core Standard: 6.NS.B.4 6th Grade Math**