Go Math! Grade 1, Chapter 4: Subtraction Strategies
In this unit, first graders learn strategies for subtracting within 20: counting back 1, 2, or 3; thinking of an addition fact; and making a ten. A fact like 15 - 8 becomes "8 plus what makes 15?" These strategies mirror the addition ones from the last unit, and next they explore how addition and subtraction are related through fact families.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Chapter 4?
- Using an addition fact to subtract, so 15 - 8 is solved by thinking 8 + 7 = 15. Learn more: Subtracting by finding the missing part
- Counting back 1, 2, or 3 to subtract, like saying 11, 10 for 12 - 2. Learn more: Counting on and back to add and subtract
- Subtracting within 20 by getting to ten first, such as 14 - 6 = 14 - 4 - 2. 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
If 5 + 3 = 8, what is 8 - 3?
- 3
- 5
- 8
How you can help
- Count back on the stairs: start on step 12, go down 2, and say each number as you land. Ask where you are and what subtraction that matches.
- Ask a think-addition question at the table: "We need 15 napkins and have 8 out. How many more?" Count up together from 8.
- Take away to get to ten with 14 dried beans: remove 4 to make 10, then 2 more, and ask what 14 - 6 is.
Where kids can get stuck
- Saying "12, 11" for 12 - 2 and answering 11, counting the starting number.
- Counting back by ones for 15 - 13 and landing on 3 instead of 2.
- Taking the wrong amount to reach ten, turning 14 - 6 into 14 - 4 - 4.
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
- subtract
- Take an amount away, or find how far apart two numbers are.
- difference
- The answer when you subtract, like 2 in 9 - 7 = 2.
- count back
- Start at one number and count down to subtract.
- think addition
- Solve a take-away fact by asking what to add, like 8 + ? = 10.
- make a ten
- Split a number to fill a ten first, like 8 + 5 = 8 + 2 + 3.
- related facts
- Facts that use the same numbers, like 6 + 4 = 10 and 10 - 4 = 6.
Ready to build your child’s confidence with subtraction strategies?
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 Go Math! Grade 1 Chapter 4 cover?
Go Math! Grade 1 Chapter 4 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.