enVision Mathematics Grade 4, Topic 9: Addition and Subtraction of Fractions
In this unit, your child adds and subtracts fractions and mixed numbers with like denominators, like 3/8 + 4/8 or 3 1/4 − 1 3/4. They break fractions into unit fractions, such as 3/4 = 1/4 + 1/4 + 1/4, and solve story problems. It builds on equivalent fractions and leads into multiplying a fraction by a whole number.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Topic 9?
- Adding and subtracting fractions and mixed numbers with like denominators, breaking fractions into unit fractions, and solving story problems with them. Learn more: Adding and subtracting fractions and mixed numbers
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 sum is equal to 4/5?
- 1/5 + 1/5 + 1/5
- 1/4 + 1/4 + 1/4 + 1/4
- 1/5 + 1/5 + 1/5 + 1/5
How you can help
- Measure ingredients for a fruit salad or trail mix with a 1/4 cup. Fill it three times and say it aloud together: one fourth, two fourths, three fourths.
- Talk about pizza leftovers. If a pizza has 8 slices and your family eats 3/8 at lunch and 4/8 at dinner, ask how much was eaten and how much is left.
- Add up walks in parts of a mile. If you walk 1 1/2 miles one day and 2 1/2 miles the next, ask your child for the total and how the halves combine.
Where kids can get stuck
- Adding the denominators too, writing 5/12 + 6/12 = 11/24, which is smaller than one of the starting fractions.
- Subtracting the smaller fraction from the larger, so 3 1/4 − 1 3/4 becomes 2 2/4.
- Thinking a fraction can never be more than 1, so 7/4 looks like a mistake.
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
- unit fraction
- A fraction with 1 as its numerator, like 1/4 or 1/8.
- mixed number
- A whole number and a fraction together, like 2 1/4.
- like denominators
- Denominators that are the same, as in 3/8 and 5/8.
- decompose
- To break a number or fraction into parts, like 3/4 = 1/4 + 1/4 + 1/4.
- numerator
- The top number of a fraction, telling how many equal parts are counted.
- denominator
- The bottom number of a fraction, telling how many equal parts make one whole.
- fraction greater than 1
- A fraction whose numerator is larger than its denominator, like 7/4.
Ready to build your child’s confidence with adding and subtracting 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.
Join the club
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 4 Topic 9 cover?
enVision Mathematics Grade 4 Topic 9 covers this math standard. Each one links to what it means, sample questions, and teaching strategies.
- 4.NF.B.3: Add and subtract fractions with the same denominator, like 5/12 + 6/12.
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.