← 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 480 · 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. 1.14 + 19 =
  2. 2.69 − 9 =
  3. 3.26 + 29 =
  4. 4.296 − 99 =
  5. 5.73 − 29 =
  6. 6.42 − 19 =
  7. 7.78 − 29 =
  8. 8.259 + 99 =
  9. 9.506 − 99 =
  10. 10.59 − 29 =
  11. 11.102 − 29 =
  12. 12.185 + 99 =
  13. 13.25 − 9 =
  14. 14.12 + 19 =
  15. 15.25 + 19 =
  16. 16.22 + 9 =
  17. 17.38 + 9 =
  18. 18.39 − 9 =
  19. 19.31 − 9 =
  20. 20.383 + 99 =
  21. 21.46 + 29 =
  22. 22.16 + 19 =
  23. 23.28 − 9 =
  24. 24.169 − 99 =
  25. 25.52 − 9 =
  26. 26.29 + 19 =
  27. 27.119 + 99 =
  28. 28.180 − 99 =
  29. 29.72 − 9 =
  30. 30.803 − 99 =
  31. 31.44 − 29 =
  32. 32.61 − 29 =
  33. 33.24 + 19 =
  34. 34.735 + 99 =
  35. 35.19 + 29 =
  36. 36.213 + 99 =
  37. 37.51 − 9 =
  38. 38.622 − 99 =
  39. 39.60 − 9 =
  40. 40.519 + 99 =

Answer key

  1. 33
  2. 60
  3. 55
  4. 197
  5. 44
  6. 23
  7. 49
  8. 358
  9. 407
  10. 30
  11. 73
  12. 284
  13. 16
  14. 31
  15. 44
  16. 31
  17. 47
  18. 30
  19. 22
  20. 482
  21. 75
  22. 35
  23. 19
  24. 70
  25. 43
  26. 48
  27. 218
  28. 81
  29. 63
  30. 704
  31. 15
  32. 32
  33. 43
  34. 834
  35. 48
  36. 312
  37. 42
  38. 523
  39. 51
  40. 618

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