← 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 963 · 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. 1.741 + 99 =
  2. 2.40 − 29 =
  3. 3.14 − 9 =
  4. 4.251 + 99 =
  5. 5.41 + 9 =
  6. 6.70 + 9 =
  7. 7.717 + 99 =
  8. 8.83 − 9 =
  9. 9.25 + 19 =
  10. 10.64 − 19 =
  11. 11.63 − 29 =
  12. 12.53 − 9 =
  13. 13.62 + 19 =
  14. 14.795 − 99 =
  15. 15.414 − 99 =
  16. 16.49 − 29 =
  17. 17.289 − 99 =
  18. 18.17 − 9 =
  19. 19.66 + 19 =
  20. 20.23 − 9 =
  21. 21.72 + 29 =
  22. 22.13 − 9 =
  23. 23.47 + 19 =
  24. 24.35 + 9 =
  25. 25.83 − 19 =
  26. 26.24 − 19 =
  27. 27.32 + 19 =
  28. 28.23 − 19 =
  29. 29.62 + 9 =
  30. 30.75 − 9 =
  31. 31.700 + 99 =
  32. 32.49 + 29 =
  33. 33.35 − 29 =
  34. 34.69 + 9 =
  35. 35.14 + 19 =
  36. 36.79 − 29 =
  37. 37.228 − 99 =
  38. 38.86 − 19 =
  39. 39.20 + 29 =
  40. 40.80 + 29 =

Answer key

  1. 840
  2. 11
  3. 5
  4. 350
  5. 50
  6. 79
  7. 816
  8. 74
  9. 44
  10. 45
  11. 34
  12. 44
  13. 81
  14. 696
  15. 315
  16. 20
  17. 190
  18. 8
  19. 85
  20. 14
  21. 101
  22. 4
  23. 66
  24. 44
  25. 64
  26. 5
  27. 51
  28. 4
  29. 71
  30. 66
  31. 799
  32. 78
  33. 6
  34. 78
  35. 33
  36. 50
  37. 129
  38. 67
  39. 49
  40. 109

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