Addition Within 10: practice solutions, Grade 1 – download the PDF

1 Marbles in a bag ★★★

We put two groups together, so we add: \(2+4\). Count on from 4: 5, 6.

\(2+4=6\). There are 6 marbles in the bag.

2 Birds on a fence ★★★

We start with 5 and add 3 more: \(5+3\). Count on: 6, 7, 8.

\(5+3=8\). There are 8 birds on the fence.

3 Read the picture ★★★

There are 3 orange counters and 4 blue counters. We count all of them: 1, 2, 3, 4, 5, 6, 7.

\(3+4=7\). The sum is 7.

4 Read the ten frame ★★★

There are 6 orange counters and 2 blue counters. Count on from 6: 7, 8.

\(6+2=8\). There are 8 counters in all.

5 Adding zero ★★★

When we add 0, the number does not change.

1. \(8+0=8\)
2. \(0+6=6\)
3. \(9+0=9\)
4. \(0+0=0\)

6 Hop on the number line ★★★

From 5 we hop 3 steps: 6, 7, 8.

\(5+3=8\). We land on 8.

7 True or false? ★★★

1. True, because \(2+5=7\).
2. False, because \(4+4=8\), not 9.
3. False, because adding 0 does not change 6, so \(6+0=6\).
4. True, because \(1+8=9\).

8 Make ten ★★★

Use the number bonds for 10.

1. \(6+4=10\), so the missing number is 4.
2. \(3+7=10\), so the missing number is 7.
3. \(2+8=10\), so the missing number is 2.
4. \(5+5=10\), so the missing number is 5.

9 Turn-around facts ★★★

We swap the two numbers. The sum stays the same.

1. \(3+6=9\) and \(6+3=9\)
2. \(2+7=9\) and \(7+2=9\)
3. \(1+5=6\) and \(5+1=6\)

10 Missing number ★★★

Count on from the first number until you reach the sum.

1. From 5 to 9 we count on 6, 7, 8, 9: that is 4 steps. So \(5+4=9\).
2. \(6+2=8\), so the missing number is 6.
3. \(3+4=7\), so the missing number is 4.
4. \(0+6=6\), so the missing number is 0.

11 Cookies on a plate ★★★

We start with 4 and add 5 more: \(4+5\). Count on: 5, 6, 7, 8, 9.

\(4+5=9\). There are 9 cookies on the plate.

12 Number bonds ★★★

Each pair of parts must make 10.

1. \(3+7=10\), so the missing part is 7.
2. \(4+6=10\), so the missing part is 4.

13 Greater than, less than, or equal? ★★★

Find each sum first, then compare.

1. \(7\) and \(8\): \(3+4<2+6\).
2. \(7\) and \(7\): \(5+2=4+3\).
3. \(6\) and \(5\): \(6+0>1+4\).
4. \(4\) and \(3\): \(2+2>3+0\).

14 Complete the table ★★★

We ask: what do we add to the first part to get 10?

\(1+9=10\), \(4+6=10\), \(7+3=10\), \(10+0=10\).

15 Three numbers ★★★

1. \(2+3=5\), then \(5+4=9\). So \(2+3+4=9\).
2. \(1+4=5\), then \(5+3=8\). So \(1+4+3=8\).
3. \(5+0=5\), then \(5+4=9\). So \(5+0+4=9\).
4. \(2+2=4\), then \(4+2=6\). So \(2+2+2=6\).

16 Find the mistake ★★★

Sam: Adding 0 does not change the number. 6 plus none is still 6. The correct sentence is \(6+0=6\).

Lena: If we start at 4 and hop 3 steps we count 5, 6, 7. We land on 7, not 8. The correct sentence is \(4+3=7\).

17 Pairs that make ten ★★★

Use the number bonds for 10.

• \(3+7=10\)
• \(4+6=10\)
• \(2+8=10\)

The card 5 is left. It needs another 5 to make 10, and there is only one 5. The card with no partner is 5.

18 Crayon box ★★★

We add the three groups: \(3+2+4\). First, \(3+2=5\). Then, \(5+4=9\).

\(3+2+4=9\). There are 9 crayons in the box.

19 Same sum, other order ★★★

1. \(2+7\) is the same as \(7+2\). The missing number is 7.
2. \(4+5\) is the same as \(5+4\). The missing number is 4.
3. \(8+1\) is the same as \(1+8\). The missing number is 8.

20 All the ways to make 8 ★★★

We start with 0 and keep adding the number needed to reach 8.

\(0+8=8\), \(1+7=8\), \(2+6=8\), \(3+5=8\), \(4+4=8\), \(5+3=8\), \(6+2=8\), \(7+1=8\), \(8+0=8\).

There are 9 sentences. Notice that most come in turn-around pairs, like \(2+6\) and \(6+2\).

21 Zyro’s garden story ★★★

\(4+5=9\). Zyro has 9 plants in all.

The turn-around sentence is \(5+4=9\).

The sums match because the order of the two numbers does not matter when we add. We still have the same total of plants.