Kindergarten · K.OA.A.4

Making 10 in kindergarten

Making 10 means finding the number that goes with another number to make 10. In kindergarten, your child starts with any number from 1 to 9 and finds its partner, such as 6 and 4. Your child shows the answer with objects, a drawing or a short number sentence like $6 + 4 = 10$ .

What the standard says

The official Common Core wording, quoted exactly. The plain version follows.

K.OA.A.4 For any number from 1 to 9, find the number that makes 10 when added to the given number, e.g., by using objects or drawings, and record the answer with a drawing or equation.

What it means, in plain words

Ten matters because our numbers are built from groups of ten. Children who know the pairs that make 10 by heart add and subtract faster in 1st and 2nd grade. Teachers often call these pairs "partners of 10" or "friends of 10".

The pairs are $1 + 9$ , $2 + 8$ , $3 + 7$ , $4 + 6$ and $5 + 5$ . Counting each pair both ways ( $2 + 8$ and $8 + 2$ ), there are nine ways to make 10 with numbers from 1 to 9. A ten-frame helps a lot with making 10. It is a box of 10 squares in two rows of 5. Your child fills some squares with counters and counts the empty squares to see how many more are needed.

Your child records each answer with a drawing or an equation. An equation is a number sentence with an equal sign, such as $2 + 8 = 10$ .

Your child should be able to:

Find the number that makes 10 with any number from 1 to 9
Use fingers, counters or a ten-frame to show how many more make 10
Show the answer with a drawing or an equation such as $4 + 6 = 10$
Name several ways to make 10

Example

There are 6 apples in a basket. How many more apples does it take to make 10?

Put 6 counters on a ten-frame, one for each apple. Four squares stay empty.
Count on from 6 while touching each empty square: 7, 8, 9, 10. That is 4 more.
$6 + 4 = 10$ , so it takes 4 more apples to make 10.

Example

Your child holds up 8 fingers. How many more fingers make 10?

Two hands have 10 fingers in all.
8 fingers are up. Count the fingers that are still down: 1, 2.
$8 + 2 = 10$ , so 2 more fingers make 10.

Where children usually get stuck

To find what goes with 5, your child counts "5, 6, 7, 8, 9, 10" on fingers and answers 6.
The count starts on the number that is already there, so that number gets counted twice.
What helps. Use a ten-frame and count only the empty squares. Say the start number out loud first, then touch and count from the next number.
Your child knows $5 + 5 = 10$ but counts from 1 every time to find the partner of 2 or 4.
Each pair was learned as a separate fact. The child does not yet see the pattern: when one number goes up by 1, its partner goes down by 1.
What helps. Line up 10 toy cars and put a pencil between two of them. Move the pencil one car at a time and say both groups out loud each time.
Your child puts counters all over a ten-frame, with gaps in both rows, and loses track of how many squares are empty.
Scattered counters make no shape the eye can read, so every count has to start over.
What helps. Fill the top row first, from left to right. A full top row is 5 at a glance, and the empty squares are easy to count.

Try four practice questions

Real kindergarten questions from our question bank, easiest first. Answer them right here, check each one, and see a worked solution for any question.

1Warm-up
The number bond below shows 10 split into two parts. One part is missing. Which number makes 10?
A
1
B
4
C
6
D
9
Show the answer and how to solve it
The missing part is 9. We know this because 1 plus 9 makes 10.
1. 1Look at the number bond. The whole is 10. One part is 1. The other part is missing.
2. 2Find the number that adds to 1 to make 10. Count up from 1 to 10: 2, 3, 4, 5, 6, 7, 8, 9, 10. We added 9 numbers to reach 10, so the partner of 1 is 9.
3. 3Check by adding the parts:
Common mistake. A common mistake is picking the part that is already shown (1) instead of finding the missing partner. Here, 1 needs the partner 9 to make 10.
The idea underneath. Every number from 1 to 9 has a partner that makes 10. The make-10 pairs are: 1 and 9, 2 and 8, 3 and 7, 4 and 6, 5 and 5.
2On level
Maria looked at the ten-frames below. Then she wrote an equation.
Maria's equation:
$\displaystyle 7 + 3 = 10$
Select the statement that best describes Maria's work.
A
Maria's total is wrong.
B
Maria used subtraction instead of adding.
C
Maria counted the colors wrong.
D
Maria's answer matches the picture.
Show the answer and how to solve it
Maria's equation matches the picture. She wrote $7 + 3 = 10$ , and the picture shows 7 yellow and 3 blue counters — both numbers and the total are correct.
1. 1Look at the ten-frames. Count the yellow counters: 7. Count the blue counters: 3. The picture shows $7 + 3$ .
2. 2Now look at Maria's equation. She wrote $7 + 3 = 10$ .
3. 3Compare. The picture shows 7 yellow — Maria wrote 7. The picture shows 3 blue — Maria wrote 3. Her total is 10, and she used a plus sign. Her equation matches the picture.
4. 4The statement that best describes Maria's work is "Maria's answer matches the picture."
Common mistake. A common mistake is picking "Maria counted the colors wrong" because students may rush and not check carefully. But Maria's numbers (7 and 3) do match the picture's counts (7 yellow and 3 blue), and her total of 10 is correct.
The idea underneath. When all three parts of an equation match the picture — both numbers and the total — the equation is correct.
3On level
Look at the equation below.
$\displaystyle 4 + \underline{\phantom{00}} = 10$
What number goes in the blank to make 10?
A
5
B
7
C
4
D
6
Show the answer and how to solve it
The missing number is $6$ because $4 + 6 = 10$ .
1. 1Look at the equation. We need to find the number that adds to $4$ to make $10$ .
2. 2Count up from $4$ : $5, 6, 7, 8, 9, 10$ . That's $6$ steps.
3. 3So the missing number is $6$ .
Common mistake. A common mistake is picking $4$ (the number already shown in the equation) or $10$ (the target sum). The blank is for the missing part — the number that adds to $4$ to make $10$ .
The idea underneath. Make- $10$ pairs are: $1$ and $9$ , $2$ and $8$ , $3$ and $7$ , $4$ and $6$ , and $5$ and $5$ . If you know one part, the other is what's left to reach $10$ .
4Stretch
The number bond shows two parts that make 10. Type the missing part.
Show the answer and how to solve it
Answer. 7
The missing part is 7. Together, 3 and 7 make 10.
1. 1Look at the number bond. The whole is 10. One part is 3, and the other part is missing.
2. 2Find the missing part. Count up from 3 to 10: 4, 5, 6, 7, 8, 9, 10. That is 7 more steps, so the missing part is 7.
3. 3Check: 3 and 7 make 10.
Common mistake. A common mistake is typing 3 (the part that is already shown) instead of the missing part, or typing 10 (the whole) instead of one of the parts.
The idea underneath. The pairs that make 10 are 1 and 9, 2 and 8, 3 and 7, 4 and 6, and 5 and 5. When you know one part, you can find the other by counting up to 10.