← 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 464 · 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. 1.66 + 19 =
  2. 2.771 − 99 =
  3. 3.28 + 9 =
  4. 4.16 + 29 =
  5. 5.58 + 9 =
  6. 6.60 + 19 =
  7. 7.328 − 99 =
  8. 8.48 + 29 =
  9. 9.25 + 19 =
  10. 10.29 + 9 =
  11. 11.472 + 99 =
  12. 12.148 + 99 =
  13. 13.19 + 9 =
  14. 14.129 + 99 =
  15. 15.33 + 29 =
  16. 16.35 + 19 =
  17. 17.215 − 99 =
  18. 18.19 + 19 =
  19. 19.15 + 9 =
  20. 20.27 − 9 =
  21. 21.47 + 9 =
  22. 22.437 − 99 =
  23. 23.68 − 19 =
  24. 24.49 + 29 =
  25. 25.63 + 19 =
  26. 26.46 + 19 =
  27. 27.75 − 19 =
  28. 28.34 − 9 =
  29. 29.598 + 99 =
  30. 30.48 + 19 =
  31. 31.42 − 19 =
  32. 32.776 + 99 =
  33. 33.67 − 9 =
  34. 34.83 − 29 =
  35. 35.40 − 19 =
  36. 36.77 − 9 =
  37. 37.39 + 19 =
  38. 38.35 − 19 =
  39. 39.59 − 9 =
  40. 40.22 − 9 =

Answer key

  1. 85
  2. 672
  3. 37
  4. 45
  5. 67
  6. 79
  7. 229
  8. 77
  9. 44
  10. 38
  11. 571
  12. 247
  13. 28
  14. 228
  15. 62
  16. 54
  17. 116
  18. 38
  19. 24
  20. 18
  21. 56
  22. 338
  23. 49
  24. 78
  25. 82
  26. 65
  27. 56
  28. 25
  29. 697
  30. 67
  31. 23
  32. 875
  33. 58
  34. 54
  35. 21
  36. 68
  37. 58
  38. 16
  39. 50
  40. 13

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