← 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 788 · 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. 1.44 + 9 =
  2. 2.31 + 9 =
  3. 3.57 − 19 =
  4. 4.56 + 19 =
  5. 5.12 + 19 =
  6. 6.29 − 19 =
  7. 7.26 + 29 =
  8. 8.46 − 19 =
  9. 9.176 + 99 =
  10. 10.64 + 29 =
  11. 11.29 − 9 =
  12. 12.27 − 19 =
  13. 13.74 − 9 =
  14. 14.66 + 29 =
  15. 15.62 + 9 =
  16. 16.12 − 9 =
  17. 17.700 − 99 =
  18. 18.56 + 29 =
  19. 19.56 + 9 =
  20. 20.65 + 9 =
  21. 21.78 + 9 =
  22. 22.22 − 19 =
  23. 23.45 + 19 =
  24. 24.379 − 99 =
  25. 25.43 + 29 =
  26. 26.435 − 99 =
  27. 27.40 + 29 =
  28. 28.70 + 29 =
  29. 29.37 − 29 =
  30. 30.31 − 9 =
  31. 31.102 − 29 =
  32. 32.98 − 29 =
  33. 33.545 − 99 =
  34. 34.48 − 29 =
  35. 35.40 − 19 =
  36. 36.68 − 19 =
  37. 37.63 + 19 =
  38. 38.59 − 9 =
  39. 39.26 − 9 =
  40. 40.19 + 9 =

Answer key

  1. 53
  2. 40
  3. 38
  4. 75
  5. 31
  6. 10
  7. 55
  8. 27
  9. 275
  10. 93
  11. 20
  12. 8
  13. 65
  14. 95
  15. 71
  16. 3
  17. 601
  18. 85
  19. 65
  20. 74
  21. 87
  22. 3
  23. 64
  24. 280
  25. 72
  26. 336
  27. 69
  28. 99
  29. 8
  30. 22
  31. 73
  32. 69
  33. 446
  34. 19
  35. 21
  36. 49
  37. 82
  38. 50
  39. 17
  40. 28

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