Go Math! Grade 4, Chapter 2: Multiply by 1-Digit Numbers
In this unit, your child multiplies numbers up to four digits by a one-digit number, using place value, rounding to estimate, and partial products. They also learn to read multiplication as a comparison and solve "times as many" and multi-step story problems. It follows the place value unit and leads into multiplying two-digit numbers.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Chapter 2?
- Writing a comparison sentence and an equation together, like "21 is 3 times as many as 7" and 21 = 3 × 7. Learn more: Reading multiplication as "times as many"
- Telling "times as many" problems from "more than" problems, and solving each with a drawing and an equation. Learn more: Story problems about "times as many"
- Solving two-step problems, like buying several packs and then one more item, and checking with an estimate. Learn more: Multi-step story problems and leftovers
- Multiplying 2-, 3-, and 4-digit numbers by 1-digit numbers, like 4 × 2,315, with partial products and regrouping. Learn more about multiplying large numbers by a one-digit number: Multiplying large numbers by a one-digit number · Learn more about multiplying two two-digit 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
A man is 6 feet tall. A giraffe is 3 times as tall as the man. Which equation finds g, the giraffe's height in feet?
- g = 3 × 6
- 6 = 3 × g
- g = 3 + 6
How you can help
- Compare lengths at home. If a shoe is about 10 inches long and the couch is about 7 times as long, ask how long the couch is, then what "7 inches longer" would be.
- Turn a fact into two sentences at bedtime. Say 24 = 6 × 4 and ask for both comparisons: 24 is 6 times as many as 4, and 4 times as many as 6.
- Figure out a grocery total together. If 3 bags of oranges cost $4 each and a melon costs $5, ask your child to estimate first, then find the total.
Where kids can get stuck
- Hearing "5 times as many as 7" and answering 12, adding instead of multiplying.
- Forgetting to add a regrouped ten, so 4 × 38 comes out as 122 instead of 152.
- Reading 35 = 5 × 7 only as "5 groups of 7," without turning it into a comparison.
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
- times as many
- A way to compare two amounts by saying how many copies of one make the other.
- multiplicative comparison
- Comparing two amounts by multiplying, as in "15 is 3 times as many as 5."
- additive comparison
- Comparing two amounts by adding or subtracting, as in "15 is 10 more than 5."
- equation
- A number sentence with an equal sign, showing both sides have the same value.
- product
- The answer to a multiplication problem.
- partial products
- The smaller products you get by multiplying each place separately, which are then added together.
- regroup
- To trade 10 of one place for 1 of the next, like 10 tens for 1 hundred.
- estimate
- A close guess, often made with rounded numbers, to check whether an answer makes sense.
Want to help your child master multiplying by one-digit numbers?
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 4 Chapter 2 cover?
Go Math! Grade 4 Chapter 2 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.