Illustrative Mathematics Grade 5, Unit 6: More Decimal and Whole Number Operations
In this unit, your child sharpens multi-digit multiplication with the written method and division by two-digit numbers, then uses both to convert measurements, such as meters to centimeters or ounces to pounds. They choose efficient strategies and check with estimates. It builds on the place value and decimal unit and comes ahead of a unit on shapes on the coordinate grid.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Unit 6?
- Multiplying multi-digit numbers with the written method, like 1,425 × 36, and checking with an estimate first. Learn more: Multiplying big numbers, like 213 × 32
- Dividing by two-digit numbers, like 3,264 ÷ 48 = 68, choosing partial quotients or another efficient strategy. Learn more: Dividing by two-digit numbers, like 480 ÷ 16
- Using multiplication and division to convert units, like 128 ounces to 8 pounds or 4.2 meters to 420 centimeters. Learn more: Converting feet to yards and grams to kilograms
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
Each apple tree in an orchard grows 30 apples. The orchard has 120 trees. How many apples do the trees grow?
- 36,000
- 3,600
- 150
How you can help
- Ask how many ounces are in a 25-pound bag of rice at the store, 400. Then ask how many pounds 128 ounces is, 8.
- Count total seats together: a stadium section with 36 rows of 45 seats. Ask your child to estimate first, then find 1,620 seats.
- Ask your child to convert a long walk, like 3,200 meters, to kilometers, 3.2, then how many days of that walk add up to 16 kilometers, 5.
Where kids can get stuck
- Converting in the wrong direction, so 128 ounces becomes 128 × 16 instead of 128 ÷ 16 = 8 pounds.
- Losing track of the regrouped digits across rows, so a four-digit by two-digit product is off.
- Stopping division too early, so 3,264 ÷ 48 gives 6 with a big remainder instead of 68.
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
- What you get when you multiply numbers together.
- partial product
- The answer from multiplying one part of a number, added up to find the whole product.
- quotient
- What you get when you divide one number by another.
- divisor
- The number you divide by, like 4 in 32 ÷ 4.
- dividend
- The amount you start with and split up in a division problem.
- convert
- To change a measurement into a different unit, like feet into inches.
- ounce
- A small unit of weight; 16 ounces make 1 pound.
- centimeter
- A small metric unit of length; 100 centimeters make 1 meter.
Want to help your child master multiplying, dividing, and converting?
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 Illustrative Mathematics Grade 5 Unit 6 cover?
Illustrative Mathematics Grade 5 Unit 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.