4th Grade · Number & Operations - Fractions
4.NF.A.1: Find equal fractions, like 3/4 = 6/8, by multiplying top and bottom
4.NF.A.1 is a 4th grade Common Core math standard in Number & Operations - Fractions. Here’s what it really covers, and how you can help your students learn it.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
The standard
Explain why a fraction a/b is equivalent to a fraction (n × a)/(n × b) by using visual fraction models, with attention to how the number and size of the parts differ even though the two fractions themselves are the same size. Use this principle to recognize and generate equivalent fractions.
In plain words
Find equal fractions, like 3/4 = 6/8, by multiplying top and bottom.
Sample questions from student practice
These questions from Bobby's Math Club are the kinds of questions your students will see. You can try answering them to see what a student might see.
Question 1 of 3
What is the missing number? 4/5 = ?/10
- 4
- 9
- 8
Where students can get stuck
- Multiplying only the bottom number and saying 3/4 equals 3/8, which is a smaller amount.
- Adding the same number to the top and bottom, so 2/3 seems equal to 4/5.
- Using the multiplying rule without being able to draw or explain why 2/5 and 4/10 are the same amount.
Effective teaching strategies
- Fold a paper strip into fourths and shade 3, then fold it in half again so each fourth is cut in two, and have students count 6 shaded parts out of 8.
- Ask students to draw 2/5 and then cut every fifth into 2 equal pieces, so they see why 2/5 and 4/10 name the same amount.
- Show 3/4 and 3/8 as two strips of the same length and ask which is smaller, so students see that multiplying only the denominator changes the amount.
Units that teach this standard
Find where 4.NF.A.1 lands in the program you teach. Each unit has a guide written for families. Unit names and order vary between editions and districts, so your school’s own materials have the exact sequence.
Bridges in Mathematics
enVision Mathematics
Everyday Mathematics
i-Ready Classroom Mathematics
Illustrative Mathematics
Math Expressions
Reveal Math
Don’t see your curriculum? Contact Bobby and we’ll see if we can help!
Share it with families
Families can read Why fractions like 3/4 and 6/8 are equal for a plain-language look at this skill, with three questions to try together and ideas for helping at home.
Help every student practice fractions at home
In Bobby's Math Club, students practice at just the right level, with a hint when they need one, a clear explanation after every question, and kid-friendly videos. Unlimited practice is free for every family.
See how it works for teachers
Written by Robert “Bobby” Barnett
Bobby is an award-winning math teacher, the author of Meet Every Learner’s Needs, and the father of two elementary-school math learners. He uses Bobby’s Math Club with his own kids a few times every week. Learn more or contact Bobby.