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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

Decimal addition

Take your time. Show your thinking.

  1. 1. 16.5 + 12.2 = ____

    16.5 · 12.2 · Decimal addition

  2. 2. 16.3 + 10.4 = ____

    16.3 · 10.4 · Decimal addition

  3. 3. 16.7 + 5.3 = ____

    16.7 · 5.3 · Decimal addition

  4. 4. 9.0 + 1.5 = ____

    9.0 · 1.5 · Decimal addition

  5. 5. 12.5 + 15.2 = ____

    12.5 · 15.2 · Decimal addition

  6. 6. 1.0 + 5.0 = ____

    1.0 · 5.0 · Decimal addition

  7. 7. 18.7 + 8.7 = ____

    18.7 · 8.7 · Decimal addition

  8. 8. 18.7 + 13.2 = ____

    18.7 · 13.2 · Decimal addition

  9. 9. 8.8 + 13.2 = ____

    8.8 · 13.2 · Decimal addition

  10. 10. 2.3 + 18.9 = ____

    2.3 · 18.9 · Decimal addition

  11. 11. 6.6 + 8.4 = ____

    6.6 · 8.4 · Decimal addition

  12. 12. 10.1 + 17.7 = ____

    10.1 · 17.7 · Decimal addition
12 questions · Seed 48 · Age guidance, not curriculum certification
View the answer key
Worksheet StudioAnswer key · Ages 10-12

Decimal addition

Answers and reasoning. Review before teaching.

  1. 1. 16.5 + 12.2 = ____

    28.7

    Add 165 tenths and 122 tenths to get 287 tenths.

  2. 2. 16.3 + 10.4 = ____

    26.7

    Add 163 tenths and 104 tenths to get 267 tenths.

  3. 3. 16.7 + 5.3 = ____

    22.0

    Add 167 tenths and 53 tenths to get 220 tenths.

  4. 4. 9.0 + 1.5 = ____

    10.5

    Add 90 tenths and 15 tenths to get 105 tenths.

  5. 5. 12.5 + 15.2 = ____

    27.7

    Add 125 tenths and 152 tenths to get 277 tenths.

  6. 6. 1.0 + 5.0 = ____

    6.0

    Add 10 tenths and 50 tenths to get 60 tenths.

  7. 7. 18.7 + 8.7 = ____

    27.4

    Add 187 tenths and 87 tenths to get 274 tenths.

  8. 8. 18.7 + 13.2 = ____

    31.9

    Add 187 tenths and 132 tenths to get 319 tenths.

  9. 9. 8.8 + 13.2 = ____

    22.0

    Add 88 tenths and 132 tenths to get 220 tenths.

  10. 10. 2.3 + 18.9 = ____

    21.2

    Add 23 tenths and 189 tenths to get 212 tenths.

  11. 11. 6.6 + 8.4 = ____

    15.0

    Add 66 tenths and 84 tenths to get 150 tenths.

  12. 12. 10.1 + 17.7 = ____

    27.8

    Add 101 tenths and 177 tenths to get 278 tenths.

12 questions · Seed 48 · Age guidance, not curriculum certification
Worksheet StudioPractice pack · Ages 10-12

Decimal addition

Take your time. Show your thinking.

  1. 1. 16.5 + 12.2 = ____

    16.5 · 12.2 · Decimal addition

  2. 2. 16.3 + 10.4 = ____

    16.3 · 10.4 · Decimal addition

  3. 3. 16.7 + 5.3 = ____

    16.7 · 5.3 · Decimal addition

  4. 4. 9.0 + 1.5 = ____

    9.0 · 1.5 · Decimal addition

  5. 5. 12.5 + 15.2 = ____

    12.5 · 15.2 · Decimal addition

  6. 6. 1.0 + 5.0 = ____

    1.0 · 5.0 · Decimal addition

  7. 7. 18.7 + 8.7 = ____

    18.7 · 8.7 · Decimal addition

  8. 8. 18.7 + 13.2 = ____

    18.7 · 13.2 · Decimal addition

  9. 9. 8.8 + 13.2 = ____

    8.8 · 13.2 · Decimal addition

  10. 10. 2.3 + 18.9 = ____

    2.3 · 18.9 · Decimal addition

  11. 11. 6.6 + 8.4 = ____

    6.6 · 8.4 · Decimal addition

  12. 12. 10.1 + 17.7 = ____

    10.1 · 17.7 · Decimal addition
12 questions · Seed 48 · Age guidance, not curriculum certification
Worksheet StudioAnswer key · Ages 10-12

Decimal addition

Answers and reasoning. Review before teaching.

  1. 1. 16.5 + 12.2 = ____

    28.7

    Add 165 tenths and 122 tenths to get 287 tenths.

  2. 2. 16.3 + 10.4 = ____

    26.7

    Add 163 tenths and 104 tenths to get 267 tenths.

  3. 3. 16.7 + 5.3 = ____

    22.0

    Add 167 tenths and 53 tenths to get 220 tenths.

  4. 4. 9.0 + 1.5 = ____

    10.5

    Add 90 tenths and 15 tenths to get 105 tenths.

  5. 5. 12.5 + 15.2 = ____

    27.7

    Add 125 tenths and 152 tenths to get 277 tenths.

  6. 6. 1.0 + 5.0 = ____

    6.0

    Add 10 tenths and 50 tenths to get 60 tenths.

  7. 7. 18.7 + 8.7 = ____

    27.4

    Add 187 tenths and 87 tenths to get 274 tenths.

  8. 8. 18.7 + 13.2 = ____

    31.9

    Add 187 tenths and 132 tenths to get 319 tenths.

  9. 9. 8.8 + 13.2 = ____

    22.0

    Add 88 tenths and 132 tenths to get 220 tenths.

  10. 10. 2.3 + 18.9 = ____

    21.2

    Add 23 tenths and 189 tenths to get 212 tenths.

  11. 11. 6.6 + 8.4 = ____

    15.0

    Add 66 tenths and 84 tenths to get 150 tenths.

  12. 12. 10.1 + 17.7 = ____

    27.8

    Add 101 tenths and 177 tenths to get 278 tenths.

12 questions · Seed 48 · Age guidance, not curriculum certification