i-Ready Classroom Mathematics Grade 1, Unit 1: Addition and Subtraction Within 10
In this unit, first graders add and subtract within 10 by solving story problems, counting on and back, and using facts they already know. They learn that switching the addends, the numbers being added, gives the same sum, and they start to recall facts within 10 quickly. It opens the year, and next they stretch the same strategies to adding and subtracting within 20.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Unit 1?
- Solving story problems within 10 about adding to, taking from, putting together, and comparing groups. Learn more: Adding and subtracting story problems within 20
- Using turnaround facts, like 6 + 3 and 3 + 6, to solve a new fact from one they already know. Learn more: Adding in any order to make it easier
- Counting on from the first number to add and counting back to subtract, saying each number as they go. Learn more: Counting on and back to add and subtract
- Recalling facts within 10, including all the pairs that make 10, quickly and accurately. Learn more about adding within 20: Adding within 20 · Learn more about subtracting 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
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
- Act out stories with toy animals: "5 ducks are in the pond, and 3 more swim in. How many now?" Then let your child make up a take-away story.
- Play "how many hiding?" with 10 spoons and a dish towel: hide some and ask how many are under the towel. Repeat until the pairs that make 10 are quick.
- Count on and back together while you climb stairs or walk along a path, adding and taking away steps as you go.
Where kids can get stuck
- Counting both groups from 1 every time instead of counting on.
- Applying turnaround facts to subtraction, writing 3 - 7 = 4.
- Counting the starting number when counting back, so 9 - 3 comes out as 7 instead of 6.
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
- add
- Put amounts together to find how many in all.
- subtract
- Take an amount away, or find how far apart two numbers are.
- count on
- Start at one number and count up to add.
- count back
- Start at one number and count down to subtract.
- addend
- A number being added, like 3 and 4 in 3 + 4.
- sum
- The answer when you add, like 7 in 3 + 4 = 7.
- difference
- The answer when you subtract, like 2 in 9 - 7 = 2.
- turnaround fact
- The same addends in the other order, like 3 + 5 and 5 + 3.
Want to help your child master adding within 10?
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 i-Ready Classroom Mathematics Grade 1 Unit 1 cover?
i-Ready Classroom 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.