← Add and take away 9, 19 and 99 lesson New set →

Adding 9, 19 and 99 Mental Maths Worksheet

Mental maths lesson 4: Add and take away 9, 19 and 99 · Set 346 · 40 questions
TalentJR

How to do it in your head (Round and adjust): Add 9, 19, 99: add 10, 20, 100, then take 1 away. Take away 9, 19, 99: take away 10, 20, 100, then add 1 back. Ask yourself: did I use too much or too little?

NameDateTime takenScore ___ / 40
  1. 1.32 + 9 =
  2. 2.21 + 29 =
  3. 3.66 + 29 =
  4. 4.82 − 19 =
  5. 5.31 − 19 =
  6. 6.25 − 9 =
  7. 7.39 − 19 =
  8. 8.36 − 29 =
  9. 9.24 + 19 =
  10. 10.14 + 9 =
  11. 11.34 − 19 =
  12. 12.45 − 19 =
  13. 13.76 − 9 =
  14. 14.71 + 9 =
  15. 15.61 + 9 =
  16. 16.41 + 19 =
  17. 17.74 − 29 =
  18. 18.66 + 19 =
  19. 19.43 + 29 =
  20. 20.70 + 29 =
  21. 21.107 − 29 =
  22. 22.28 + 19 =
  23. 23.308 − 99 =
  24. 24.15 − 9 =
  25. 25.532 − 99 =
  26. 26.74 + 19 =
  27. 27.676 − 99 =
  28. 28.16 − 9 =
  29. 29.92 − 29 =
  30. 30.30 − 19 =
  31. 31.47 + 9 =
  32. 32.46 − 19 =
  33. 33.69 − 9 =
  34. 34.32 − 19 =
  35. 35.25 + 9 =
  36. 36.400 + 99 =
  37. 37.15 + 29 =
  38. 38.34 + 9 =
  39. 39.22 + 29 =
  40. 40.49 − 9 =

Answer key

  1. 41
  2. 50
  3. 95
  4. 63
  5. 12
  6. 16
  7. 20
  8. 7
  9. 43
  10. 23
  11. 15
  12. 26
  13. 67
  14. 80
  15. 70
  16. 60
  17. 45
  18. 85
  19. 72
  20. 99
  21. 78
  22. 47
  23. 209
  24. 6
  25. 433
  26. 93
  27. 577
  28. 7
  29. 63
  30. 11
  31. 56
  32. 27
  33. 60
  34. 13
  35. 34
  36. 499
  37. 44
  38. 43
  39. 51
  40. 40

Free mental maths lessons, practice and worksheets at talentjr.in/mental-maths