← 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 219 · 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. 1.37 − 19 =
  2. 2.35 − 29 =
  3. 3.71 + 9 =
  4. 4.69 − 19 =
  5. 5.81 − 19 =
  6. 6.72 − 19 =
  7. 7.618 + 99 =
  8. 8.76 − 19 =
  9. 9.41 − 19 =
  10. 10.268 − 99 =
  11. 11.707 − 99 =
  12. 12.29 + 19 =
  13. 13.45 + 29 =
  14. 14.767 + 99 =
  15. 15.13 + 29 =
  16. 16.72 − 9 =
  17. 17.48 + 19 =
  18. 18.79 − 9 =
  19. 19.256 + 99 =
  20. 20.56 + 29 =
  21. 21.41 + 9 =
  22. 22.91 − 19 =
  23. 23.44 + 29 =
  24. 24.321 − 99 =
  25. 25.85 − 19 =
  26. 26.51 + 19 =
  27. 27.78 − 19 =
  28. 28.73 − 9 =
  29. 29.83 − 29 =
  30. 30.36 − 9 =
  31. 31.17 + 9 =
  32. 32.20 + 9 =
  33. 33.35 + 29 =
  34. 34.76 + 9 =
  35. 35.43 + 19 =
  36. 36.12 + 29 =
  37. 37.33 − 9 =
  38. 38.109 − 29 =
  39. 39.25 + 29 =
  40. 40.102 − 29 =

Answer key

  1. 18
  2. 6
  3. 80
  4. 50
  5. 62
  6. 53
  7. 717
  8. 57
  9. 22
  10. 169
  11. 608
  12. 48
  13. 74
  14. 866
  15. 42
  16. 63
  17. 67
  18. 70
  19. 355
  20. 85
  21. 50
  22. 72
  23. 73
  24. 222
  25. 66
  26. 70
  27. 59
  28. 64
  29. 54
  30. 27
  31. 26
  32. 29
  33. 64
  34. 85
  35. 62
  36. 41
  37. 24
  38. 80
  39. 54
  40. 73

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