Go Math! Grade 1, Chapter 5: Addition and Subtraction Relationships
In this unit, first graders connect addition and subtraction through fact families, groups of facts that share the same three numbers. They solve story problems with the missing number in any spot, decide whether equations are true or false, and find unknowns in sentences like 5 = ? - 3. It pulls together the strategies from the last two units, and next they count and model numbers to 120.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Chapter 5?
- Solving story problems where the start, the change, or the result is the missing number, using a model or equation. Learn more: Adding and subtracting story problems within 20
- Adding and subtracting within 20 using fact families, so 7 + 6 = 13 also tells them 13 - 6 = 7. Learn more about adding within 20: Adding within 20 · Learn more about subtracting within 20
- Deciding whether equations like 9 = 5 + 4 or 8 - 2 = 3 + 3 are true or false. Learn more: What the equal sign really means
- Finding the missing number in equations like 12 - ? = 4 or ? + 5 = 11. Learn more: Missing numbers, like 8 + ? = 11
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
- Pick three numbers, like 6, 7, and 13, and ask your child to say all four facts in the family. Write them on a napkin or sticky note.
- Tell a story with the start missing: "Some kids were at the park; 4 more came, and now there are 11. How many were there at first?"
- Say a number sentence like "10 equals 6 plus 4" and ask true or false. Mix in some with the answer first and some that are false.
Where kids can get stuck
- Calling 9 = 5 + 4 wrong because the answer is written first.
- Answering 16 for 12 - ? = 4, adding the two numbers they see.
- Answering 15 for "some kids, then 4 more, now 11," adding instead of finding the start.
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
- fact family
- Addition and subtraction facts that use the same three numbers, like 3, 4, and 7.
- related facts
- Facts that use the same numbers, like 6 + 4 = 10 and 10 - 4 = 6.
- equation
- A number sentence with an equal sign, like 5 + 3 = 8.
- equal sign
- The symbol = that means "the same amount as."
- true
- An equation is true when both sides are the same amount.
- false
- An equation is false when the two sides are different amounts.
- unknown
- The number we don't know yet, shown with a box or question mark.
Ready to build your child’s confidence with fact families?
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 5 cover?
Go Math! Grade 1 Chapter 5 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.