Least Common Denominator

Finding common ground for fractions to play together!

What is the Least Common Denominator?

The Least Common Denominator (LCD) is the smallest number that two or more denominators can divide into evenly.
When fractions have different denominators, we can't compare or add them directly. That's where LCD comes to the rescue! It helps us rewrite fractions so they all have the same denominator, making math operations much easier.

How to Find the LCD

1️⃣ List the multiples of each denominator

2️⃣ Find the smallest number that appears in all lists

3️⃣ That's your LCD! Now you can rewrite the fractions

Let's Practice Together!

Example 1: Find LCD of 4 and 6

Multiples of 4: 4, 8, 12, 16, 20...

Multiples of 6: 6, 12, 18, 24, 30...

The smallest common number is 12!

Example 2: Interactive Practice

Find the LCD of and

Your answer:

Parent Tips 🌟

  • Baking fractions: Use measuring cups to show how 1/2 cup + 1/3 cup needs a common measure (6ths) to add properly.
  • LCD scavenger hunt: Have your child find household items that come in different fractions (pizza slices, chocolate bars) and calculate their LCDs.
  • Skip counting: Practice multiples by skip counting (e.g., for 4: 4, 8, 12, 16...) to build the foundation for finding LCDs.

Ready for More Math Fun?

Continue your child's math journey with our interactive lessons and games!

Download iMath App