← 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 676 · 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. 1.95 − 19 =
  2. 2.80 + 9 =
  3. 3.224 + 99 =
  4. 4.33 − 19 =
  5. 5.65 + 19 =
  6. 6.33 + 9 =
  7. 7.34 − 9 =
  8. 8.41 + 29 =
  9. 9.38 + 9 =
  10. 10.54 + 9 =
  11. 11.61 + 29 =
  12. 12.42 − 19 =
  13. 13.77 + 19 =
  14. 14.48 + 9 =
  15. 15.81 − 29 =
  16. 16.16 + 29 =
  17. 17.97 − 29 =
  18. 18.68 − 9 =
  19. 19.64 − 9 =
  20. 20.268 + 99 =
  21. 21.52 − 9 =
  22. 22.44 + 19 =
  23. 23.67 − 29 =
  24. 24.17 + 9 =
  25. 25.170 + 99 =
  26. 26.707 + 99 =
  27. 27.158 − 99 =
  28. 28.17 + 29 =
  29. 29.450 + 99 =
  30. 30.570 + 99 =
  31. 31.143 + 99 =
  32. 32.93 − 19 =
  33. 33.108 − 29 =
  34. 34.37 + 9 =
  35. 35.276 − 99 =
  36. 36.52 + 19 =
  37. 37.15 + 19 =
  38. 38.46 − 9 =
  39. 39.669 + 99 =
  40. 40.47 + 29 =

Answer key

  1. 76
  2. 89
  3. 323
  4. 14
  5. 84
  6. 42
  7. 25
  8. 70
  9. 47
  10. 63
  11. 90
  12. 23
  13. 96
  14. 57
  15. 52
  16. 45
  17. 68
  18. 59
  19. 55
  20. 367
  21. 43
  22. 63
  23. 38
  24. 26
  25. 269
  26. 806
  27. 59
  28. 46
  29. 549
  30. 669
  31. 242
  32. 74
  33. 79
  34. 46
  35. 177
  36. 71
  37. 34
  38. 37
  39. 768
  40. 76

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