Eureka Math² Grade 2, Module 1: Addition and Subtraction Within 20 and Word Problems to 100
In this unit, your child sharpens addition and subtraction facts within 20 with strategies like making ten and using doubles. They solve word problems with numbers up to 100, drawing tape diagrams, simple bars that show the parts and the whole, to decide whether to add or subtract. This sets up adding and subtracting within 100 with tens and ones next.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Module 1?
- Solving word problems to 100 with the unknown in different places, using tape diagrams to show the story. Learn more: One- and two-step story problems within 100
- Using make ten, doubles, and related facts to add and subtract within 20 quickly and flexibly. Learn more about adding fluently within 20: Adding fluently within 20 · Learn more about subtracting fluently within 20
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 80 minus 20?
- 50
- 60
- 70
How you can help
- Turn toy cleanup into a word problem: "There were 40 blocks out and you put 25 away. How many are still out?" Ask for a quick drawing.
- Ask doubles while setting the table, like "four plates and four more," then ask for the near double, four plus five.
- Pick a fact like 9 + 7 and ask your child to show you how making ten helps, by thinking 9 + 1 + 6.
Where kids can get stuck
- Starting a word problem by adding the two numbers before picturing what is happening.
- Missing that 15 − 7 and 7 + 8 = 15 are related, and solving each one from scratch.
- Drawing a tape diagram whose bars don't match the story's parts and whole.
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
- tape diagram
- A drawing of bars, like strips of tape, that shows the parts and the whole of a story.
- part
- One of the amounts that together make up the whole in a story problem.
- whole
- The total amount, made of all the parts put together.
- unknown
- The missing number in a problem, often shown with a box or a question mark.
- make ten
- Filling up a ten first to add, like 9 + 6 = 9 + 1 + 5 = 15.
- doubles
- Facts where a number is added to itself, like 7 + 7 = 14.
- related facts
- Adding and subtracting facts with the same numbers, like 8 + 5 = 13 and 13 − 5 = 8.
- equation
- A number sentence with an equal sign, like 9 + 4 = 13.
Ready to build your child’s confidence with word problems to 100?
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 1 cover?
Eureka Math² Grade 2 Module 1 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.