enVision Mathematics Grade 3, Topic 9: Fluently Add and Subtract Within 1000
In this unit, your child builds speed and accuracy adding and subtracting numbers up to 1,000 with written methods. They regroup, trading 10 ones for 1 ten or 10 tens for 1 hundred, and learn to subtract across zeros, as in 400 − 156. Two-step story problems use these skills. Next, multiplication returns, this time with multiples of 10.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Topic 9?
- Adding and subtracting three-digit numbers on paper with regrouping, including tricky cases like 400 − 156 = 244. Learn more about adding within 1,000: Adding within 1,000 · Learn more about subtracting within 1,000
- Solving two-step stories with three-digit numbers, such as a 500-page book with 120 pages read Monday and 95 read Tuesday. Learn more: Story problems with two steps
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
What is 245 + 132?
- 113
- 277
- 377
How you can help
- Use mile signs on a ride or a trail map on a walk to ask how far is left, such as 250 miles in all with 130 already traveled (120).
- Ask your child to check a subtraction by adding back, such as 137 + 175 = 312 after finding 312 − 175, and explain why it works.
- Keep score in a card game and ask your child to add the points from two rounds, such as 365 and 278 (643).
Where kids can get stuck
- Getting tangled when subtracting across zeros, as in 400 − 156, and skipping a step in the regrouping.
- Lining up digits in the wrong columns, so the ones of one number sit under the tens of the other.
- Stopping after one step of a two-step problem, giving the pages read instead of the pages left.
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
- regroup
- To trade between places, like turning 1 hundred into 10 tens to subtract.
- sum
- The answer to an addition problem.
- difference
- The answer to a subtraction problem.
- place value
- The value of a digit because of where it is in a number.
- hundreds
- Groups of 100; the 3 in 347 means 3 hundreds.
- ones
- The place on the far right of a whole number, worth single units.
- column
- A line going straight up and down, such as the tens column.
Want to help your child master three-digit addition and subtraction?
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 3 Topic 9 cover?
enVision Mathematics Grade 3 Topic 9 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.