Everyday Mathematics Kindergarten, Unit 7: Subtraction and Decomposition
In this unit, your child takes numbers apart and puts them back together. They show subtraction with objects and drawings, break numbers up to 10 into two parts in different ways, and find the number that makes 10. It returns to numbers after the shape and length work of the last unit and leads into more measuring next.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Unit 7?
- Showing taking away by crossing out pictures or removing toys, and writing equations such as 5 - 2 = 3. Learn more about showing addition in many ways: Showing addition in many ways · Learn more about showing subtraction in many ways
- Breaking numbers up to 10 into two parts in more than one way, such as 6 = 4 + 2 and 6 = 5 + 1. Learn more: Splitting numbers up to 10 into two parts
- Finding how many more make 10 from any number from 1 to 9, such as knowing 7 needs 3 more. Learn more: Finding the number that makes 10
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
Start at 7 and hop back 2. Where do you land?
- 2
- 9
- 5
How you can help
- Hide some of 6 crackers under a cup while your child looks away. Show the ones left and ask how many are hiding. Then try a different split of the same 6.
- Hold up some fingers and ask how many more make 10. If you show 7, your child shows the other 3. Take turns being the one who asks.
- Tell take-away stories at snack time: you have 5 apple slices and eat 2. Have your child draw 5 circles and cross out 2 to show how many are left.
Where kids can get stuck
- Drawing 5 circles and then 2 more circles for a take-away problem, instead of crossing out 2 of the 5.
- Including the starting number when counting up to 10, so from 6 they count five more instead of four.
- Finding one way to split a number, like 5 = 4 + 1, and thinking it is the only way.
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
- To take some away and find how many are left.
- minus
- The sign - that means subtract, or take away.
- equation
- A number sentence with an equal sign, like 3 + 2 = 5.
- equal sign
- The sign = that means both sides are the same amount.
- part
- One of the pieces that make up a whole number.
- whole
- The total amount, before it is split into parts.
- make 10
- Finding two numbers that add up to 10, like 7 and 3.
- ten-frame
- A box of 10 spaces, in two rows of 5, for showing numbers.
Ready to build your child’s confidence with taking numbers apart?
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 Everyday Mathematics Kindergarten Unit 7 cover?
Everyday Mathematics Kindergarten Unit 7 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.