Small practice. Bright discoveries.Explore the free starter collection
worksheetstudio.
Sign in
Back to worksheets
MathsAges 10-12

Decimal addition

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

New variationTry interactive challengeBrowse templates

Choose “Save as PDF” to keep a copy. Use your browser’s paper setting for A4 or Letter.

Worksheet StudioPractice pack · Ages 10-12

Decimal addition

Take your time. Show your thinking.

  1. 1. 5.1 + 18.0 = ____

    5.1 · 18.0 · Decimal addition

  2. 2. 18.2 + 2.2 = ____

    18.2 · 2.2 · Decimal addition

  3. 3. 2.1 + 2.2 = ____

    2.1 · 2.2 · Decimal addition

  4. 4. 10.1 + 6.1 = ____

    10.1 · 6.1 · Decimal addition

  5. 5. 14.3 + 11.3 = ____

    14.3 · 11.3 · Decimal addition

  6. 6. 15.3 + 15.2 = ____

    15.3 · 15.2 · Decimal addition

  7. 7. 3.2 + 6.8 = ____

    3.2 · 6.8 · Decimal addition

  8. 8. 2.9 + 16.8 = ____

    2.9 · 16.8 · Decimal addition

  9. 9. 11.4 + 15.2 = ____

    11.4 · 15.2 · Decimal addition

  10. 10. 19.2 + 16.1 = ____

    19.2 · 16.1 · Decimal addition

  11. 11. 8.4 + 3.3 = ____

    8.4 · 3.3 · Decimal addition

  12. 12. 6.9 + 15.3 = ____

    6.9 · 15.3 · Decimal addition
12 questions · Seed 46 · 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. 5.1 + 18.0 = ____

    23.1

    Add 51 tenths and 180 tenths to get 231 tenths.

  2. 2. 18.2 + 2.2 = ____

    20.4

    Add 182 tenths and 22 tenths to get 204 tenths.

  3. 3. 2.1 + 2.2 = ____

    4.3

    Add 21 tenths and 22 tenths to get 43 tenths.

  4. 4. 10.1 + 6.1 = ____

    16.2

    Add 101 tenths and 61 tenths to get 162 tenths.

  5. 5. 14.3 + 11.3 = ____

    25.6

    Add 143 tenths and 113 tenths to get 256 tenths.

  6. 6. 15.3 + 15.2 = ____

    30.5

    Add 153 tenths and 152 tenths to get 305 tenths.

  7. 7. 3.2 + 6.8 = ____

    10.0

    Add 32 tenths and 68 tenths to get 100 tenths.

  8. 8. 2.9 + 16.8 = ____

    19.7

    Add 29 tenths and 168 tenths to get 197 tenths.

  9. 9. 11.4 + 15.2 = ____

    26.6

    Add 114 tenths and 152 tenths to get 266 tenths.

  10. 10. 19.2 + 16.1 = ____

    35.3

    Add 192 tenths and 161 tenths to get 353 tenths.

  11. 11. 8.4 + 3.3 = ____

    11.7

    Add 84 tenths and 33 tenths to get 117 tenths.

  12. 12. 6.9 + 15.3 = ____

    22.2

    Add 69 tenths and 153 tenths to get 222 tenths.

12 questions · Seed 46 · Age guidance, not curriculum certification
Worksheet StudioPractice pack · Ages 10-12

Decimal addition

Take your time. Show your thinking.

  1. 1. 5.1 + 18.0 = ____

    5.1 · 18.0 · Decimal addition

  2. 2. 18.2 + 2.2 = ____

    18.2 · 2.2 · Decimal addition

  3. 3. 2.1 + 2.2 = ____

    2.1 · 2.2 · Decimal addition

  4. 4. 10.1 + 6.1 = ____

    10.1 · 6.1 · Decimal addition

  5. 5. 14.3 + 11.3 = ____

    14.3 · 11.3 · Decimal addition

  6. 6. 15.3 + 15.2 = ____

    15.3 · 15.2 · Decimal addition

  7. 7. 3.2 + 6.8 = ____

    3.2 · 6.8 · Decimal addition

  8. 8. 2.9 + 16.8 = ____

    2.9 · 16.8 · Decimal addition

  9. 9. 11.4 + 15.2 = ____

    11.4 · 15.2 · Decimal addition

  10. 10. 19.2 + 16.1 = ____

    19.2 · 16.1 · Decimal addition

  11. 11. 8.4 + 3.3 = ____

    8.4 · 3.3 · Decimal addition

  12. 12. 6.9 + 15.3 = ____

    6.9 · 15.3 · Decimal addition
12 questions · Seed 46 · Age guidance, not curriculum certification
Worksheet StudioAnswer key · Ages 10-12

Decimal addition

Answers and reasoning. Review before teaching.

  1. 1. 5.1 + 18.0 = ____

    23.1

    Add 51 tenths and 180 tenths to get 231 tenths.

  2. 2. 18.2 + 2.2 = ____

    20.4

    Add 182 tenths and 22 tenths to get 204 tenths.

  3. 3. 2.1 + 2.2 = ____

    4.3

    Add 21 tenths and 22 tenths to get 43 tenths.

  4. 4. 10.1 + 6.1 = ____

    16.2

    Add 101 tenths and 61 tenths to get 162 tenths.

  5. 5. 14.3 + 11.3 = ____

    25.6

    Add 143 tenths and 113 tenths to get 256 tenths.

  6. 6. 15.3 + 15.2 = ____

    30.5

    Add 153 tenths and 152 tenths to get 305 tenths.

  7. 7. 3.2 + 6.8 = ____

    10.0

    Add 32 tenths and 68 tenths to get 100 tenths.

  8. 8. 2.9 + 16.8 = ____

    19.7

    Add 29 tenths and 168 tenths to get 197 tenths.

  9. 9. 11.4 + 15.2 = ____

    26.6

    Add 114 tenths and 152 tenths to get 266 tenths.

  10. 10. 19.2 + 16.1 = ____

    35.3

    Add 192 tenths and 161 tenths to get 353 tenths.

  11. 11. 8.4 + 3.3 = ____

    11.7

    Add 84 tenths and 33 tenths to get 117 tenths.

  12. 12. 6.9 + 15.3 = ____

    22.2

    Add 69 tenths and 153 tenths to get 222 tenths.

12 questions · Seed 46 · Age guidance, not curriculum certification