Math Expressions Grade 5, Unit 1: Addition and Subtraction with Fractions
In this unit, your child starts the year with fractions, adding and subtracting ones with different denominators, like 2/3 + 1/4. They rename fractions as equivalent fractions with a common denominator, work with mixed numbers, and solve story problems, using estimates to judge whether answers make sense. Next comes adding and subtracting decimals, which builds on the same ideas.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Unit 1?
- Adding and subtracting fractions and mixed numbers with unlike denominators by first renaming them with a common denominator. Learn more: Adding and subtracting fractions like 2/3 + 1/4
- Solving word problems that add or subtract fractions, then using estimation to decide whether the answer is reasonable. 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
- Use a ruler marked in eighths to add two lengths, like 2 1/4 inches and 1 3/8 inches. Lay the objects end to end and measure to check the total.
- Talk about how much of a pizza or a pan of brownies is left after people take pieces. Ask your child to write the fractions and subtract.
- Plan a short walk in fractions of a mile, like 1/2 mile out and 1/3 mile more. Ask your child how far that is, and how much farther to reach 1 mile.
Where kids can get stuck
- Adding the tops and the bottoms, so 1/2 + 1/3 becomes 2/5 instead of 5/6.
- Renaming only the denominator, so 3/4 gets written as 3/8 instead of 6/8 before adding.
- Accepting 3/7 as the sum of 2/5 + 1/2, without noticing that the sum must be more than 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
- numerator
- The top number in a fraction, telling how many parts you have.
- denominator
- The bottom number in a fraction, telling how many equal parts make a whole.
- common denominator
- A denominator that two or more fractions share, like 12 for 2/3 and 1/4.
- equivalent fractions
- Fractions that name the same amount, like 1/2 and 3/6.
- mixed number
- A whole number and a fraction together, like 2 1/2.
- estimate
- A close guess found by rounding or using easy numbers.
- reasonable
- Making sense for the problem, close to what an estimate predicts.
Ready to build your child’s confidence with 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 Math Expressions Grade 5 Unit 1 cover?
Math Expressions Grade 5 Unit 1 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.