Zearn Math Grade 2, Mission 5: Addition and Subtraction Within 1,000 with Word Problems to 100
In this unit, your child adds and subtracts with numbers up to 1,000. They regroup ones, tens, and hundreds, sometimes more than once in the same problem, and choose a smart strategy like counting up or adjusting a number. They explain why their steps work. It builds on work within 200 and leads into equal groups, the start of multiplication and division.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Mission 5?
- Adding and subtracting within 1,000, like 538 + 295 or 600 - 248, including problems that regroup twice. Learn more about adding within 1,000: Adding within 1,000 · Learn more about subtracting within 1,000
- Using 10 more, 10 less, 100 more, and 100 less to solve problems in their heads, such as 538 + 100. Learn more: Adding or taking away 10 or 100 mentally
- Explaining why a shortcut works, such as adding 300 and then taking away 5 to add 295. Learn more about explaining why addition strategies work: Explaining why addition strategies work · Learn more about explaining why subtraction strategies work
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 toy store had 450 toy cars and sold 120 of them. How many toy cars are left?
- 320
- 570
- 330
How you can help
- Ask your child to add 295 to a number by adding 300 and then taking 5 away. Then ask them why that gives the same answer.
- Count up to find a difference, like how many pages it takes to get from page 248 to page 600: 248 to 250, then to 300, then to 600.
- Name a number on a walk or ride, like 538, and ask for 100 more and 10 less. Ask which digit changes each time.
Where kids can get stuck
- Subtracting 300 to take away 295, then taking away 5 more instead of adding 5 back.
- Struggling to regroup across zeros in 600 - 248, where a hundred must become tens before any ones.
- Writing each column's total straight into the answer, so 538 + 295 becomes 71213 instead of 833.
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 10 ones for 1 ten, or 10 tens for 1 hundred, and back again.
- compose
- To put parts together to make a bigger unit, like 10 tens making 1 hundred.
- decompose
- To break a number into parts, like 82 = 80 + 2, or 1 hundred into 10 tens.
- hundreds
- Groups of 100. The 3 in 352 means 3 hundreds, or 300.
- strategy
- A plan or way to solve a problem.
- difference
- The answer when you subtract. In 13 - 5 = 8, the difference is 8.
- sum
- The answer when you add. In 8 + 5 = 13, the sum is 13.
Want to help your child master addition and subtraction within 1,000?
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 Zearn Math Grade 2 Mission 5 cover?
Zearn Math Grade 2 Mission 5 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.