Fun math worksheet featuring 16 double-digit addition problems surrounded by cute sea creatures like whales and dolphins.

Let’s solve each double-digit addition problem step by step. We’ll add the ones place first, then the tens place. If the ones add up to 10 or more, we carry over to the tens.

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1) 99 + 59
Ones: 9 + 9 = 18 → write 8, carry 1
Tens: 9 + 5 + 1 (carry) = 15 → write 15
→ 158

2) 76 + 13
Ones: 6 + 3 = 9
Tens: 7 + 1 = 8
→ 89

3) 31 + 11
Ones: 1 + 1 = 2
Tens: 3 + 1 = 4
→ 42

4) 63 + 63
Ones: 3 + 3 = 6
Tens: 6 + 6 = 12
→ 126

5) 54 + 87
Ones: 4 + 7 = 11 → write 1, carry 1
Tens: 5 + 8 + 1 = 14
→ 141

6) 14 + 43
Ones: 4 + 3 = 7
Tens: 1 + 4 = 5
→ 57

7) 14 + 95
Ones: 4 + 5 = 9
Tens: 1 + 9 = 10
→ 109

8) 98 + 29
Ones: 8 + 9 = 17 → write 7, carry 1
Tens: 9 + 2 + 1 = 12
→ 127

9) 15 + 22
Ones: 5 + 2 = 7
Tens: 1 + 2 = 3
→ 37

10) 61 + 68
Ones: 1 + 8 = 9
Tens: 6 + 6 = 12
→ 129

11) 70 + 53
Ones: 0 + 3 = 3
Tens: 7 + 5 = 12
→ 123

12) 38 + 80
Ones: 8 + 0 = 8
Tens: 3 + 8 = 11
→ 118

13) 51 + 34
Ones: 1 + 4 = 5
Tens: 5 + 3 = 8
→ 85

14) 99 + 65
Ones: 9 + 5 = 14 → write 4, carry 1
Tens: 9 + 6 + 1 = 16
→ 164

15) 10 + 74
Ones: 0 + 4 = 4
Tens: 1 + 7 = 8
→ 84

16) 73 + 86
Ones: 3 + 6 = 9
Tens: 7 + 8 = 15
→ 159

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Final Answer:
1) 158
2) 89
3) 42
4) 126
5) 141
6) 57
7) 109
8) 127
9) 37
10) 129
11) 123
12) 118
13) 85
14) 164
15) 84
16) 159