Eureka Math² Grade 2, Module 5: Addition and Subtraction Within 1,000
In this unit, your child adds and subtracts within 1,000. They use place value drawings, number lines, and a written method, regrouping across hundreds, tens, and ones. They also add or take away 10 or 100 in their head and explain why their strategies work. Next, the year moves on to shapes, fractions, and time.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Module 5?
- Adding and subtracting three-digit numbers with drawings and a written method, regrouping when a place needs it. Learn more about adding within 1,000: Adding within 1,000 · Learn more about subtracting within 1,000
- Adding or subtracting 10 or 100 mentally from numbers between 100 and 900, such as 100 more than 650. Learn more: Adding or taking away 10 or 100 mentally
- Explaining why their steps work, such as why 10 tens become a hundred in a sum. 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
- Add the prices of two items on a menu or flyer, like 249 and 125, and let your child explain each trade.
- Say a number from a sign, and ask for 100 less, then 10 less, and keep going until you reach a number under 100.
- Solve one problem two ways together, such as 503 − 198 by counting up and by a written method, and compare the answers.
Where kids can get stuck
- Subtracting the smaller digit from the larger in every column, so 621 − 385 becomes 364.
- Saying 10 more than 693 is 6103 or 603 instead of 703.
- Explaining the steps but not the reason, unsure what a crossed-out digit really means.
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
- Trading 10 ones for 1 ten, or 1 ten for 10 ones, to add or subtract.
- compose
- To put parts together to make a bigger unit, like 10 ones making 1 ten.
- decompose
- To break a number into parts, like 1 hundred into 10 tens.
- hundreds
- Groups of 100. In 706, the 7 means 7 hundreds, or 700.
- mentally
- In your head, without writing it down or using objects.
- number line
- A line with numbers in order at equal spaces, used to count, add, and subtract.
- strategy
- A way of solving a problem, like making a ten or counting on.
Ready to build your child’s confidence with adding and subtracting to 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.
Join the club
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 Eureka Math² Grade 2 Module 5 cover?
Eureka Math² Grade 2 Module 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.