Comparing fractions is a math skill that many upper elementary students struggle with. The key is finding a strategy that works for them. Typically, once I teach students how to use the butterfly method to compare fractions, I see lightbulbs go off around the classroom as students begin to get it.
Why the Butterfly Method Works
I get why many students struggle with comparing fractions. When I was an upper elementary student, I struggled with it too.
My teachers only ever taught me one way to compare fractions, and it was tedious. Having to find a common denominator and convert each of the fractions took a long time and left lots of room for error.
In my first year as a 5th-grade teacher, a colleague taught me how to use the butterfly method to compare fractions. As soon as she showed me, all I could think was… why was I never taught this in elementary school!? It would have saved me so much time and stress.
The reason why the butterfly method works so well for so many students is because it is simple. No finding common denominators. No converting fractions. No drawing models. If students know their basic multiplication facts, they can easily compare fractions in seconds!
How to Use the Butterfly Method to Compare Fractions
Use the following steps to compare two fractions using the butterfly method.
Step 1: Make sure the fractions are written vertically. They should be written side-by-side.
Step 2: Draw a circle around the denominator of the first fraction and the numerator of the second fraction. Multiply the circled numbers. Write the product next to the circled numerator (second fraction).
Step 3: Draw a circle around the denominator of the second fraction and the numerator of the first fraction. Multiply the circled numbers. Write the product next to the circled numerator (first fraction).
Step 4: Compare the products. The fraction with the greater product written next to it is the greater fraction.
You may be wondering… why is it called the butterfly method? When you draw the two circles, it looks like a butterfly.
What about Equivalent Fractions?
It’s also easy to identify equivalent fractions when using the butterfly method. If the products next to each fraction are the same, the fractions are equivalent.
Resources to Teach Comparing Fractions
Using the butterfly method to compare fractions is just one strategy I show in my Compare and Order Fractions Unit Plans. The unit plans have EVERYTHING you need to teach comparing fractions including—
- detailed lesson plans
- worksheets
- games and centers
- digital activities
- assessments
- word wall cards
In addition to the detailed unit plans, you can also find the following resources to teach comparing fractions in my store:
When students have the right strategy, comparing fractions doesn’t have to be hard. Using the butterfly method to compare fractions is by far the best strategy I have found for teaching this math skill. I hope it helps your students too!
