Addition within 100

Add 2-digit numbers up to 100, including carrying

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Try each question. If you're stuck, leave it and come back. The answer key is on the last page.

1
What is 25 add 13? 25 + 13 = ___
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2
Sam has 23 marbles. His mum gives him 15 more. How many does he have now? A) 38 B) 28 C) 48 D) 35
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3
What is 50 + 27? 50 + 27 = ___
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4
What is 20 + 30? 20 + 30 = ___
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5
Put these sums in order from smallest answer to largest. Put these in order: 47 + 32, 20 + 15, 30 + 20, 40 + 12
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6
What is 18 + 24? A) 32 B) 42 C) 44 D) 38
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7
What is 36 + 48? 36 + 48 = ___
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8
What is 56 + 28? 56 + 28 = ___
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9
What is 67 + 25? 67 + 25 = ___
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10
What is 75 + 19? 75 + 19 = ___
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Answer key

Addition within 100 · for parents and teachers

1
38
25 + 13 = 38. The tens give 30 and the ones give 8.
2
38
23 + 15 = 38. So Sam has 38 marbles.
3
77
50 + 27 = 77. Adding to a whole ten is easier.
4
50
20 + 30 = 50.
5
20 + 15, 30 + 20, 40 + 12, 47 + 32
20+15=35, 30+20=50, 40+12=52, 47+32=79. In order: 35, 50, 52, 79.
6
42
18 + 24 = 42. The ones add to 12, so we carry 1 ten over.
7
84
36 + 48 = 84. The ones make 14, so we carry 1 to get 8 tens.
8
84
56 + 28 = 84.
9
92
67 + 25 = 92.
10
94
75 + 19 = 94.