Illustrative Mathematics Grade 1, Unit 1: Adding Subtracting and Working with Data
In this unit, first graders add and subtract within 10, counting on and back and building quick recall of small facts. They also collect data, or information, sort it into categories, and answer questions about it. It opens the year, and next they solve many kinds of addition and subtraction story problems, including ones where the start is the missing number.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Unit 1?
- Solving small adding and subtracting stories within 10 and showing their thinking with objects, drawings, or equations. Learn more: Adding and subtracting story problems within 20
- Counting on to add and counting back to subtract, so 6 + 2 becomes 7, 8. Learn more: Counting on and back to add and subtract
- Adding and subtracting within 10, using combinations they know, like 5 and 5 or 7 and 3. Learn more about adding within 20: Adding within 20 · Learn more about subtracting within 20
- Sorting objects into categories, counting each group, and answering how many more are in one group. Learn more: Sorting, tallying, and reading simple charts
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
I had some toy cars. My friend gave me 3 more cars. Now I have 8 cars in total. How many toy cars did I have at first?
- 3
- 5
- 8
How you can help
- Sort a pile of socks or utensils into three groups and count each. Ask how many more are in the biggest group than in the smallest.
- Play a board game where you roll and count on from your current spot, saying each number aloud as you move.
- Ask a quick question as you put away toys: "There are 10 cars, and 7 are in the box. How many are still out?"
Where kids can get stuck
- Starting over at 1 for 6 + 2 instead of counting on from 6.
- Counting an item twice while sorting, so the group totals don't add up.
- Answering with one group's count when asked how many more it has than another group.
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
- count on
- Start at one number and count up to add.
- count back
- Start at one number and count down to subtract.
- equation
- A number sentence with an equal sign, like 5 + 3 = 8.
- data
- Information collected to answer a question, like everyone's favorite fruit.
- category
- A group that things are sorted into.
- sort
- Put things into groups that are alike in some way.
- how many more
- A question asking how much bigger one amount is than another.
Ready to build your child’s confidence with adding within 10 and sorting?
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 Illustrative Mathematics Grade 1 Unit 1 cover?
Illustrative Mathematics Grade 1 Unit 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.