Go Math! Grade 5, Chapter 6: Add and Subtract Fractions with Unlike Denominators
In this unit, your child adds and subtracts fractions with unlike denominators. They find a common denominator, work with mixed numbers, including renaming when subtracting, and use benchmarks like 0, 1/2, and 1 to check answers. It begins the fraction part of the year after the decimal units and leads into multiplying fractions next.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Chapter 6?
- Finding a common denominator to add and subtract, including renaming mixed numbers, like 4 1/6 − 1 1/2 = 2 2/3. Learn more: Adding and subtracting fractions like 2/3 + 1/4
- Estimating with benchmarks like 0, 1/2, and 1 to check fraction word problems, then solving them exactly. 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
- Ask your child to add two walk lengths, like 1 1/2 miles and 3/4 mile. Let them estimate about 2 miles first, then find 2 1/4 miles.
- Look at a recipe that uses 2/3 cup of sugar and 1/4 cup of honey. Ask how much sweetener in all, 11/12 cup, and whether that is less than 1 cup.
- Ask a renaming question with a ribbon: it is 4 1/6 yards long and you use 1 1/2 yards. How much is left? Help your child find 2 2/3 yards.
Where kids can get stuck
- Subtracting mixed numbers without renaming, so 4 1/6 − 1 1/2 becomes 3 1/3 instead of 2 2/3.
- Adding numerators and denominators, so 2/3 + 1/4 becomes 3/7 instead of 11/12.
- Forgetting to simplify or rename, leaving an answer like 2 9/6 instead of 3 1/2.
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
- unlike denominators
- Bottom numbers that are different, as in 2/3 and 1/4.
- common denominator
- The same bottom number shared by two fractions, so their parts are the same size.
- equivalent fractions
- Fractions that name the same amount, like 1/2 and 3/6.
- mixed number
- A number written as a whole number plus a fraction, like 3 3/4.
- rename
- To write a number another way, like 4 1/6 as 3 7/6.
- benchmark fraction
- A friendly fraction, such as 1/2, used to check whether an answer is sensible.
- simplify
- To rewrite a fraction with smaller numbers that name the same amount, like 4/6 as 2/3.
Ready to build your child’s confidence with unlike denominators?
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 Go Math! Grade 5 Chapter 6 cover?
Go Math! Grade 5 Chapter 6 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.