MathsAges 10-12

Decimal addition

Add numbers in tenths. Keep the decimal places aligned as you calculate. Review suitability for your learners before teaching.

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Worksheet StudioPractice pack · Ages 10-12

Take your time. Show your thinking.

12 questions · Seed 44 · Age guidance, not curriculum certification

View the answer key

Worksheet StudioAnswer key · Ages 10-12

Answers and reasoning. Review before teaching.

1. 19.3 + 19.4 = ____
38.7
Add 193 tenths and 194 tenths to get 387 tenths.
2. 18.5 + 16.3 = ____
34.8
Add 185 tenths and 163 tenths to get 348 tenths.
3. 10.1 + 12.8 = ____
22.9
Add 101 tenths and 128 tenths to get 229 tenths.
4. 16.2 + 7.2 = ____
23.4
Add 162 tenths and 72 tenths to get 234 tenths.
5. 19.0 + 1.7 = ____
20.7
Add 190 tenths and 17 tenths to get 207 tenths.
6. 5.6 + 6.7 = ____
12.3
Add 56 tenths and 67 tenths to get 123 tenths.
7. 15.2 + 17.2 = ____
32.4
Add 152 tenths and 172 tenths to get 324 tenths.
8. 3.4 + 17.4 = ____
20.8
Add 34 tenths and 174 tenths to get 208 tenths.
9. 3.0 + 12.9 = ____
15.9
Add 30 tenths and 129 tenths to get 159 tenths.
10. 8.6 + 5.6 = ____
14.2
Add 86 tenths and 56 tenths to get 142 tenths.
11. 5.2 + 18.6 = ____
23.8
Add 52 tenths and 186 tenths to get 238 tenths.
12. 2.1 + 10.5 = ____
12.6
Add 21 tenths and 105 tenths to get 126 tenths.

12 questions · Seed 44 · Age guidance, not curriculum certification

Worksheet StudioPractice pack · Ages 10-12

Take your time. Show your thinking.

12 questions · Seed 44 · Age guidance, not curriculum certification

Worksheet StudioAnswer key · Ages 10-12

Answers and reasoning. Review before teaching.

1. 19.3 + 19.4 = ____
38.7
Add 193 tenths and 194 tenths to get 387 tenths.
2. 18.5 + 16.3 = ____
34.8
Add 185 tenths and 163 tenths to get 348 tenths.
3. 10.1 + 12.8 = ____
22.9
Add 101 tenths and 128 tenths to get 229 tenths.
4. 16.2 + 7.2 = ____
23.4
Add 162 tenths and 72 tenths to get 234 tenths.
5. 19.0 + 1.7 = ____
20.7
Add 190 tenths and 17 tenths to get 207 tenths.
6. 5.6 + 6.7 = ____
12.3
Add 56 tenths and 67 tenths to get 123 tenths.
7. 15.2 + 17.2 = ____
32.4
Add 152 tenths and 172 tenths to get 324 tenths.
8. 3.4 + 17.4 = ____
20.8
Add 34 tenths and 174 tenths to get 208 tenths.
9. 3.0 + 12.9 = ____
15.9
Add 30 tenths and 129 tenths to get 159 tenths.
10. 8.6 + 5.6 = ____
14.2
Add 86 tenths and 56 tenths to get 142 tenths.
11. 5.2 + 18.6 = ____
23.8
Add 52 tenths and 186 tenths to get 238 tenths.
12. 2.1 + 10.5 = ____
12.6
Add 21 tenths and 105 tenths to get 126 tenths.

12 questions · Seed 44 · Age guidance, not curriculum certification