← 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 556 · 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. 1.104 − 29 =
  2. 2.20 + 29 =
  3. 3.66 − 29 =
  4. 4.39 + 19 =
  5. 5.34 − 9 =
  6. 6.45 − 19 =
  7. 7.39 + 9 =
  8. 8.35 − 29 =
  9. 9.68 + 19 =
  10. 10.68 − 29 =
  11. 11.440 + 99 =
  12. 12.53 + 29 =
  13. 13.136 + 99 =
  14. 14.477 − 99 =
  15. 15.52 + 29 =
  16. 16.92 − 19 =
  17. 17.26 + 9 =
  18. 18.38 + 9 =
  19. 19.22 + 9 =
  20. 20.55 + 19 =
  21. 21.74 − 19 =
  22. 22.299 − 99 =
  23. 23.676 − 99 =
  24. 24.70 + 29 =
  25. 25.39 − 9 =
  26. 26.552 + 99 =
  27. 27.55 + 9 =
  28. 28.482 + 99 =
  29. 29.57 − 9 =
  30. 30.830 − 99 =
  31. 31.58 − 9 =
  32. 32.668 − 99 =
  33. 33.99 − 29 =
  34. 34.199 + 99 =
  35. 35.324 + 99 =
  36. 36.71 + 19 =
  37. 37.59 + 19 =
  38. 38.29 − 19 =
  39. 39.16 + 9 =
  40. 40.57 − 19 =

Answer key

  1. 75
  2. 49
  3. 37
  4. 58
  5. 25
  6. 26
  7. 48
  8. 6
  9. 87
  10. 39
  11. 539
  12. 82
  13. 235
  14. 378
  15. 81
  16. 73
  17. 35
  18. 47
  19. 31
  20. 74
  21. 55
  22. 200
  23. 577
  24. 99
  25. 30
  26. 651
  27. 64
  28. 581
  29. 48
  30. 731
  31. 49
  32. 569
  33. 70
  34. 298
  35. 423
  36. 90
  37. 78
  38. 10
  39. 25
  40. 38

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