← 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 764 · 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. 1.51 − 29 =
  2. 2.693 + 99 =
  3. 3.32 + 29 =
  4. 4.50 − 29 =
  5. 5.54 + 9 =
  6. 6.22 + 19 =
  7. 7.390 + 99 =
  8. 8.618 − 99 =
  9. 9.52 − 9 =
  10. 10.331 + 99 =
  11. 11.17 + 9 =
  12. 12.50 − 9 =
  13. 13.305 − 99 =
  14. 14.54 − 9 =
  15. 15.14 + 9 =
  16. 16.145 + 99 =
  17. 17.24 + 9 =
  18. 18.683 + 99 =
  19. 19.170 − 99 =
  20. 20.45 − 19 =
  21. 21.55 + 19 =
  22. 22.484 − 99 =
  23. 23.68 − 19 =
  24. 24.31 + 19 =
  25. 25.67 + 9 =
  26. 26.104 − 29 =
  27. 27.20 + 9 =
  28. 28.645 + 99 =
  29. 29.193 − 99 =
  30. 30.34 − 9 =
  31. 31.100 − 29 =
  32. 32.344 + 99 =
  33. 33.21 + 9 =
  34. 34.801 − 99 =
  35. 35.64 + 19 =
  36. 36.17 + 19 =
  37. 37.26 − 19 =
  38. 38.38 + 29 =
  39. 39.144 + 99 =
  40. 40.48 − 29 =

Answer key

  1. 22
  2. 792
  3. 61
  4. 21
  5. 63
  6. 41
  7. 489
  8. 519
  9. 43
  10. 430
  11. 26
  12. 41
  13. 206
  14. 45
  15. 23
  16. 244
  17. 33
  18. 782
  19. 71
  20. 26
  21. 74
  22. 385
  23. 49
  24. 50
  25. 76
  26. 75
  27. 29
  28. 744
  29. 94
  30. 25
  31. 71
  32. 443
  33. 30
  34. 702
  35. 83
  36. 36
  37. 7
  38. 67
  39. 243
  40. 19

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