# Finding Common Denominators | Fractions | Pre-Algebra | Khan Academy

Finding Common Denominators

Practice this lesson yourself on KhanAcademy.org right now:

Watch the next lesson:

Missed the previous lesson?

Pre-Algebra on Khan Academy: No way, this isn’t your run of the mill arithmetic. This is Pre-algebra. You’re about to play with the professionals. Think of pre-algebra as a runway. You’re the airplane and algebra is your sunny vacation destination. Without the runway you’re not going anywhere. Seriously, the foundation for all higher mathematics is laid with many of the concepts that we will introduce to you here: negative numbers, absolute value, factors, multiples, decimals, and fractions to name a few. So buckle up and move your seat into the upright position. We’re about to take off!

About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We’ve also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content.

## 11 thoughts

1. Anthony Young, Jr. says:

He goes really fast

2. Hamida Choudhury says:

I understand this but I do harder ones

I’m learning this in forth grade I learned alot

4. Julia Belcher says:

I’m in 5th grade and it is easy

5. Force Phantom says:

6. Force Phantom says:

7. Patrick Benjamin Duenas says:

this helped

8. Navid Khan says:

in 2:53 u can just times 6 by 8

9. Jackie Becerra says:

thanks so much this helped me with my he☺😊

10. Severlan Hunter says:

thanks alot u hel me alot 😀

11. ieon says:

i know this is a dumb question, but how did you get the 3 multiplying the 24 from 2/8