← 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 890 · 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. 1.52 − 19 =
  2. 2.90 − 29 =
  3. 3.97 − 29 =
  4. 4.704 − 99 =
  5. 5.580 − 99 =
  6. 6.35 − 9 =
  7. 7.45 + 29 =
  8. 8.26 + 29 =
  9. 9.70 + 19 =
  10. 10.893 − 99 =
  11. 11.54 − 29 =
  12. 12.274 − 99 =
  13. 13.85 − 29 =
  14. 14.15 + 9 =
  15. 15.26 + 19 =
  16. 16.35 + 9 =
  17. 17.494 − 99 =
  18. 18.514 − 99 =
  19. 19.181 − 99 =
  20. 20.40 + 9 =
  21. 21.23 + 19 =
  22. 22.682 + 99 =
  23. 23.55 − 29 =
  24. 24.555 + 99 =
  25. 25.41 − 29 =
  26. 26.22 + 19 =
  27. 27.64 − 19 =
  28. 28.478 + 99 =
  29. 29.33 − 9 =
  30. 30.29 − 19 =
  31. 31.27 + 19 =
  32. 32.44 − 19 =
  33. 33.72 + 19 =
  34. 34.63 − 29 =
  35. 35.35 − 19 =
  36. 36.603 + 99 =
  37. 37.80 + 9 =
  38. 38.710 + 99 =
  39. 39.17 + 19 =
  40. 40.29 − 9 =

Answer key

  1. 33
  2. 61
  3. 68
  4. 605
  5. 481
  6. 26
  7. 74
  8. 55
  9. 89
  10. 794
  11. 25
  12. 175
  13. 56
  14. 24
  15. 45
  16. 44
  17. 395
  18. 415
  19. 82
  20. 49
  21. 42
  22. 781
  23. 26
  24. 654
  25. 12
  26. 41
  27. 45
  28. 577
  29. 24
  30. 10
  31. 46
  32. 25
  33. 91
  34. 34
  35. 16
  36. 702
  37. 89
  38. 809
  39. 36
  40. 20

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