← 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 651 · 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. 1.50 + 9 =
  2. 2.641 − 99 =
  3. 3.87 − 29 =
  4. 4.299 + 99 =
  5. 5.31 + 9 =
  6. 6.95 − 19 =
  7. 7.67 − 9 =
  8. 8.66 + 19 =
  9. 9.71 − 29 =
  10. 10.42 + 9 =
  11. 11.30 − 19 =
  12. 12.82 − 29 =
  13. 13.287 − 99 =
  14. 14.57 + 9 =
  15. 15.15 − 9 =
  16. 16.66 − 19 =
  17. 17.77 + 29 =
  18. 18.85 − 9 =
  19. 19.76 − 9 =
  20. 20.460 − 99 =
  21. 21.38 + 29 =
  22. 22.78 + 29 =
  23. 23.383 − 99 =
  24. 24.49 − 9 =
  25. 25.42 − 9 =
  26. 26.88 − 19 =
  27. 27.41 + 29 =
  28. 28.46 + 19 =
  29. 29.49 − 19 =
  30. 30.681 + 99 =
  31. 31.108 − 29 =
  32. 32.49 + 29 =
  33. 33.619 + 99 =
  34. 34.31 + 29 =
  35. 35.72 + 19 =
  36. 36.74 + 9 =
  37. 37.51 + 29 =
  38. 38.46 − 9 =
  39. 39.44 + 9 =
  40. 40.805 − 99 =

Answer key

  1. 59
  2. 542
  3. 58
  4. 398
  5. 40
  6. 76
  7. 58
  8. 85
  9. 42
  10. 51
  11. 11
  12. 53
  13. 188
  14. 66
  15. 6
  16. 47
  17. 106
  18. 76
  19. 67
  20. 361
  21. 67
  22. 107
  23. 284
  24. 40
  25. 33
  26. 69
  27. 70
  28. 65
  29. 30
  30. 780
  31. 79
  32. 78
  33. 718
  34. 60
  35. 91
  36. 83
  37. 80
  38. 37
  39. 53
  40. 706

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