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 49 · Age guidance, not curriculum certification

View the answer key

Worksheet StudioAnswer key · Ages 10-12

Answers and reasoning. Review before teaching.

1. 14.2 + 16.6 = ____
30.8
Add 142 tenths and 166 tenths to get 308 tenths.
2. 2.1 + 17.3 = ____
19.4
Add 21 tenths and 173 tenths to get 194 tenths.
3. 9.0 + 12.0 = ____
21.0
Add 90 tenths and 120 tenths to get 210 tenths.
4. 4.9 + 11.0 = ____
15.9
Add 49 tenths and 110 tenths to get 159 tenths.
5. 5.1 + 3.8 = ____
8.9
Add 51 tenths and 38 tenths to get 89 tenths.
6. 16.2 + 2.0 = ____
18.2
Add 162 tenths and 20 tenths to get 182 tenths.
7. 6.1 + 10.6 = ____
16.7
Add 61 tenths and 106 tenths to get 167 tenths.
8. 1.8 + 13.5 = ____
15.3
Add 18 tenths and 135 tenths to get 153 tenths.
9. 7.0 + 4.9 = ____
11.9
Add 70 tenths and 49 tenths to get 119 tenths.
10. 14.8 + 16.1 = ____
30.9
Add 148 tenths and 161 tenths to get 309 tenths.
11. 4.0 + 18.7 = ____
22.7
Add 40 tenths and 187 tenths to get 227 tenths.
12. 3.9 + 18.9 = ____
22.8
Add 39 tenths and 189 tenths to get 228 tenths.

12 questions · Seed 49 · Age guidance, not curriculum certification

Worksheet StudioPractice pack · Ages 10-12

Take your time. Show your thinking.

12 questions · Seed 49 · Age guidance, not curriculum certification

Worksheet StudioAnswer key · Ages 10-12

Answers and reasoning. Review before teaching.

1. 14.2 + 16.6 = ____
30.8
Add 142 tenths and 166 tenths to get 308 tenths.
2. 2.1 + 17.3 = ____
19.4
Add 21 tenths and 173 tenths to get 194 tenths.
3. 9.0 + 12.0 = ____
21.0
Add 90 tenths and 120 tenths to get 210 tenths.
4. 4.9 + 11.0 = ____
15.9
Add 49 tenths and 110 tenths to get 159 tenths.
5. 5.1 + 3.8 = ____
8.9
Add 51 tenths and 38 tenths to get 89 tenths.
6. 16.2 + 2.0 = ____
18.2
Add 162 tenths and 20 tenths to get 182 tenths.
7. 6.1 + 10.6 = ____
16.7
Add 61 tenths and 106 tenths to get 167 tenths.
8. 1.8 + 13.5 = ____
15.3
Add 18 tenths and 135 tenths to get 153 tenths.
9. 7.0 + 4.9 = ____
11.9
Add 70 tenths and 49 tenths to get 119 tenths.
10. 14.8 + 16.1 = ____
30.9
Add 148 tenths and 161 tenths to get 309 tenths.
11. 4.0 + 18.7 = ____
22.7
Add 40 tenths and 187 tenths to get 227 tenths.
12. 3.9 + 18.9 = ____
22.8
Add 39 tenths and 189 tenths to get 228 tenths.

12 questions · Seed 49 · Age guidance, not curriculum certification