enVision Mathematics Grade 5, Topic 7: Use Equivalent Fractions to Add and Subtract
In this unit, your child uses equivalent fractions to add and subtract fractions and mixed numbers with unlike denominators. They rewrite 1/2 and 1/3 as sixths, for example, before combining them, and use benchmarks like 1/2 to judge whether an answer is reasonable. After dividing decimals, the year turns to fractions, and the next unit multiplies them.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Topic 7?
- Rewriting fractions and mixed numbers as equivalent fractions with a common denominator, like 1/2 + 1/3 = 3/6 + 2/6 = 5/6. Learn more: Adding and subtracting fractions like 2/3 + 1/4
- Solving word problems with fractions of the same whole, and using benchmarks like 0, 1/2, and 1 to check answers. Learn more: Story problems that add and subtract fractions
Sample questions to try together
These are real questions from our practice. Tap the speaker to hear one read aloud, or the light bulb for a hint, and talk about the answer together.
Question 1 of 3
Which common denominator could you use to add 3/4 and 5/6?
- 10
- 12
- 6
How you can help
- Cut a sandwich or tortilla into halves, then cut one half into thirds. Ask your child what each small piece is called, 1/6, and how many sixths make 1/2.
- Track a walk in fractions of a mile, like 3/4 mile out and 2/3 mile back. Ask your child for the total distance, 1 5/12 miles, and to explain the twelfths.
- Ask a reasonableness question before solving: is 1/2 + 3/8 more or less than 1? Let your child explain with a drawing, then find the exact sum, 7/8.
Where kids can get stuck
- Subtracting the smaller fraction from the larger in mixed numbers, so 3 1/4 − 1 1/2 becomes 2 1/4 instead of 1 3/4.
- Adding tops and bottoms, so 1/2 + 1/4 becomes 2/6, an answer smaller than 1/2.
- Choosing to add when a problem asks how much more, so the answer is far too large.
Practice makes perfect
Bobby's Math Club has practice problems that adapt to your child’s level, each with a detailed explanation and an easy-to-follow video, so your child can build confidence in these skills one step at a time.
Words your child will hear
- equivalent fractions
- Different-looking fractions with the same value, like 2/3 and 8/12.
- common denominator
- A denominator two fractions can both be renamed with, like 12 for 1/3 and 1/4.
- numerator
- The top number of a fraction, which counts how many parts you have.
- denominator
- The bottom number of a fraction, which tells how many equal parts make a whole.
- mixed number
- A whole number and a fraction together, like 2 1/2.
- benchmark fraction
- A friendly fraction, such as 1/2, used to check whether an answer is sensible.
- reasonable
- Making sense for the problem, close to what an estimate predicts.
Ready to build your child’s confidence with equivalent fractions?
In Bobby's Math Club, your child practices these skills 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.
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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.
Which math standards does enVision Mathematics Grade 5 Topic 7 cover?
enVision Mathematics Grade 5 Topic 7 covers these math standards. Each one links to what it means, sample questions, and teaching strategies.
For teachers: Unit names and order vary between editions and districts, so your school’s own materials have the exact sequence. Learn how Bobby's Math Club can help your students grow.