enVision Mathematics Grade 1, Topic 4: Subtraction Facts to 20: Use Strategies
In this unit, first graders subtract within 20 using strategies. They count back, make a ten, and think of subtraction as finding a missing part, so 14 - 9 asks "9 plus what makes 14?" Building on the addition facts from the last unit, they see how adding and subtracting are related, which prepares them for the next unit's equations, number sentences with an equal sign.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Topic 4?
- Solving subtraction by thinking addition, so 13 - 8 becomes "What do I add to 8 to make 13?" Learn more: Subtracting by finding the missing part
- Subtracting within 20 by getting to ten first, like 15 - 7 = 15 - 5 - 2, or by using a fact family. 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 up together while you wait: "We need 15 stickers and have 9. How many more?" Count up from 9 on your fingers: 10, 11, 12, 13, 14, 15.
- Write a fact family on a napkin, like 6 + 8 = 14, 8 + 6 = 14, 14 - 6 = 8, and 14 - 8 = 6. Ask your child which fact answers which question.
- Play a take-away game with 15 dried beans: remove 5 to get to 10, then 2 more, and talk about why 15 - 7 is 8.
Where kids can get stuck
- Counting back from 15 one at a time to subtract 13, and landing on 1 or 3.
- Counting the starting number as a step, saying "8, 9, 10, that's 3" for 10 - 8.
- Missing that the known fact 6 + 4 = 10 already answers 10 - 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.
- missing addend
- The part you need to add to reach a total, like 2 in 8 + ? = 10.
- fact family
- Addition and subtraction facts that use the same three numbers, like 3, 4, and 7.
- make a ten
- Split a number to fill a ten first, like 8 + 5 = 8 + 2 + 3.
Want to help your child master subtraction facts to 20?
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 enVision Mathematics Grade 1 Topic 4 cover?
enVision Mathematics Grade 1 Topic 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.