Subtraction Within 10: practice solutions, Kindergarten – download the PDF

1 Cross out the ladybugs ★★★

Cross out 2 of the 6 ladybugs. Count the ladybugs with no cross: 4 are left.

The equation is \(6 - 2 = 4\). 4 ladybugs are left.

2 Apples in the basket ★★★

Start with 5 and take away 1. Taking away 1 gives the number just before 5, which is 4.

\(5 - 1 = 4\). 4 apples are left.

3 Read the equation ★★★

a) “Seven minus two equals five.” You start with 7, take away 2, and 5 are left.

b) “Four minus one equals three.” You start with 4, take away 1, and 3 are left.

4 Take away nothing, take away all ★★★

a) Taking away nothing changes nothing: \(3 - 0 = 3\).

b) Taking away all 3 leaves nothing: \(3 - 3 = 0\).

c) \(8 - 0 = 8\).

d) \(8 - 8 = 0\).

5 Finish the facts ★★★

a) \(4 - 2 = 2\).

b) \(5 - 3 = 2\).

c) \(3 - 1 = 2\).

d) \(2 - 1 = 1\).

You can check each one by drawing the starting group and crossing out the number you take away.

6 Fish in the pond ★★★

Cross out 3 of the 8 counters. The counters with no cross are the fish that stay.

\(8 - 3 = 5\). 5 fish stay in the pond.

7 Match the story ★★★

“Gives away” means some stickers go away, so we subtract. The matching equation is B) \(6 - 2 = 4\). Mia has 4 stickers left.

Equation A uses a plus sign, which would make the group bigger.

8 Taking 7 apart ★★★

The orange cars are the part we do not know. Whole minus the known part gives the other part.

\(7 - 3 = 4\). 4 cars are orange.

9 Blocks of two colors ★★★

The whole is 10 and one part is 6. Subtract the known part from the whole.

\(10 - 6 = 4\). There are 4 yellow blocks.

Check: 6 green and 4 yellow make 10 blocks.

10 Cupcakes at the party ★★★

Draw 9 circles and cross out 5. Four circles have no cross.

\(9 - 5 = 4\). 4 cupcakes are left on the tray.

11 Hop back on the number line ★★★

Hop back one step at a time: 7, 6, 5. You land on 5.

\(8 - 3 = 5\).

12 True or false? ★★★

a) False. Six minus two is 4, so \(6 - 2 = 4\).

b) True. Taking away all 5 leaves nothing.

c) False. Taking away nothing leaves 4, so \(4 - 0 = 4\).

13 Fact fluency challenge ★★★

a) \(5 - 2 = 3\)   b) \(4 - 3 = 1\)   c) \(3 - 3 = 0\)   d) \(5 - 4 = 1\)   e) \(4 - 2 = 2\)   f) \(2 - 0 = 2\)

Trick: \(5 - 2 = 3\) and \(5 - 3 = 2\) use the same two parts of 5.

14 Find Leo’s mistake ★★★

Leo added 6 and 4 instead of taking away. The minus sign means we take away, so the answer must be smaller than 6.

The correct equation is \(6 - 4 = 2\).

15 All the subtractions from 5 ★★★

Take away 1, 2, 3, and 4 from 5 in turn.

\(5 - 1 = 4\),   \(5 - 2 = 3\),   \(5 - 3 = 2\),   \(5 - 4 = 1\).

Notice the pattern: when the number you take away goes up by 1, the answer goes down by 1.

16 Birds leave in two steps ★★★

First step: \(10 - 3 = 7\), so 7 birds are on the fence.

Second step: \(7 - 2 = 5\).

5 birds are still on the fence.

17 How many were lost? ★★★

Hop back from 9 until you reach 6: 8, 7, 6. That is 3 hops, so she lost 3 crayons.

\(9 - 3 = 6\). Ana lost 3 crayons.

Check: 9 minus 3 leaves 6, which matches the story.

18 Which leaves more? ★★★

Story A: \(8 - 3 = 5\) balloons left.

Story B: \(8 - 5 = 3\) balloons left.

Since 5 is more than 3, Story A leaves more balloons. The more you take away, the fewer are left.

19 Two facts from one picture ★★★

Take away one part to find the other.

\(7 - 4 = 3\) and \(7 - 3 = 4\).

20 Write your own story ★★★

Many stories work. Here is one: “There are 10 frogs on a lily pad. Six frogs jump into the water. Four frogs stay on the lily pad.”

A good story starts with 10, something goes away (6), and 4 are left.

21 Make 5 left ★★★

If the answer is 5, the first number is 5 more than the number you take away.

\(10 - 5 = 5\),   \(9 - 4 = 5\),   \(8 - 3 = 5\),   \(7 - 2 = 5\),   \(6 - 1 = 5\),   \(5 - 0 = 5\).

Both numbers go down by 1 each time, and the answer stays 5.