← 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 104 · 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. 1.26 + 29 =
  2. 2.56 − 19 =
  3. 3.90 − 29 =
  4. 4.55 − 29 =
  5. 5.71 − 29 =
  6. 6.14 + 19 =
  7. 7.57 + 19 =
  8. 8.60 − 9 =
  9. 9.45 − 9 =
  10. 10.69 + 9 =
  11. 11.99 − 19 =
  12. 12.94 − 29 =
  13. 13.24 − 19 =
  14. 14.37 − 9 =
  15. 15.57 + 29 =
  16. 16.28 + 29 =
  17. 17.34 − 9 =
  18. 18.16 + 19 =
  19. 19.88 − 9 =
  20. 20.72 + 29 =
  21. 21.14 − 9 =
  22. 22.76 − 29 =
  23. 23.46 + 29 =
  24. 24.51 + 29 =
  25. 25.178 − 99 =
  26. 26.43 − 29 =
  27. 27.66 − 19 =
  28. 28.128 + 99 =
  29. 29.277 + 99 =
  30. 30.17 + 19 =
  31. 31.571 + 99 =
  32. 32.25 + 29 =
  33. 33.740 − 99 =
  34. 34.23 + 19 =
  35. 35.30 + 9 =
  36. 36.104 − 29 =
  37. 37.77 − 29 =
  38. 38.43 − 9 =
  39. 39.61 − 9 =
  40. 40.17 + 29 =

Answer key

  1. 55
  2. 37
  3. 61
  4. 26
  5. 42
  6. 33
  7. 76
  8. 51
  9. 36
  10. 78
  11. 80
  12. 65
  13. 5
  14. 28
  15. 86
  16. 57
  17. 25
  18. 35
  19. 79
  20. 101
  21. 5
  22. 47
  23. 75
  24. 80
  25. 79
  26. 14
  27. 47
  28. 227
  29. 376
  30. 36
  31. 670
  32. 54
  33. 641
  34. 42
  35. 39
  36. 75
  37. 48
  38. 34
  39. 52
  40. 46

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