enVision Mathematics Grade 5, Topic 8: Apply Understanding of Multiplication to Multiply Fractions
In this unit, your child multiplies with fractions. They find a fraction of a whole number, multiply two fractions, find areas of rectangles with fraction side lengths, and predict whether multiplying by a fraction gives a larger or smaller answer. It builds on the equivalent fraction work from the unit before, uses everyday problems throughout, and prepares for dividing fractions next.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Topic 8?
- Finding a fraction of a number, like 2/3 of 12 = 8, and multiplying fractions like 2/3 × 4/5 = 8/15. Learn more: Multiplying fractions, like 2/3 × 4/5
- Telling whether a product will be bigger or smaller than a number, like 3/4 × 20 being less than 20. Learn more: When multiplying makes a number smaller
- Solving everyday problems with fractions and mixed numbers, like finding the area of a 2 1/2 by 1 1/2 foot board. Learn more: Multiplying fractions in real life, like recipes
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
The blue part of the rectangle shows 1/3 × 2/5, and the whole rectangle is 1. What is 1/3 × 2/5?
- 2/15
- 2/13
- 3/8
How you can help
- Ask fraction-of questions at the store: if a $20 shirt is on sale for 3/4 of its price, what does it cost? Let your child find 1/4 first, $5, then 3/4, $15.
- Double or halve a recipe with mixed numbers, like 1 3/4 cups of flour. Ask your child for 2 times and 1/2 times that amount, 3 1/2 and 7/8 cups.
- Play “bigger or smaller?” on a walk: say a number like 24 and a fraction like 5/4. Your child says whether the product will grow or shrink before working it out.
Where kids can get stuck
- Multiplying the whole number by the top and bottom, so 3 × 2/5 becomes 6/15 instead of 6/5.
- Expecting 3/4 × 20 to be more than 20, because multiplying has always made numbers grow.
- Multiplying the whole numbers and the fractions separately, so 2 1/2 × 1 1/2 becomes 2 1/4, not 3 3/4.
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
- product
- The answer to a multiplication problem, like 24 in 6 × 4 = 24.
- factor
- A number you multiply by another number to get a product.
- unit fraction
- A fraction with 1 as its numerator, like 1/3 or 1/8.
- scaling
- Thinking of multiplication as stretching or shrinking an amount.
- mixed number
- A number written as a whole number plus a fraction, like 3 3/4.
- area
- The amount of flat space a shape covers, measured in square units.
- of
- In math, often means multiply, so 1/2 of 8 means 1/2 × 8.
Want to help your child master multiplying 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 8 cover?
enVision Mathematics Grade 5 Topic 8 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.