← 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 914 · 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. 1.25 + 19 =
  2. 2.52 − 29 =
  3. 3.41 + 29 =
  4. 4.28 − 9 =
  5. 5.64 − 19 =
  6. 6.68 + 9 =
  7. 7.28 + 9 =
  8. 8.19 + 19 =
  9. 9.61 + 19 =
  10. 10.617 + 99 =
  11. 11.619 − 99 =
  12. 12.61 − 19 =
  13. 13.79 − 9 =
  14. 14.72 − 9 =
  15. 15.156 − 99 =
  16. 16.66 + 9 =
  17. 17.206 − 99 =
  18. 18.13 + 19 =
  19. 19.31 + 9 =
  20. 20.865 − 99 =
  21. 21.892 − 99 =
  22. 22.54 − 19 =
  23. 23.27 − 9 =
  24. 24.91 − 19 =
  25. 25.69 + 9 =
  26. 26.80 + 19 =
  27. 27.30 − 19 =
  28. 28.43 − 29 =
  29. 29.78 + 9 =
  30. 30.48 + 19 =
  31. 31.611 − 99 =
  32. 32.331 − 99 =
  33. 33.17 + 29 =
  34. 34.715 + 99 =
  35. 35.30 + 19 =
  36. 36.44 + 19 =
  37. 37.45 − 9 =
  38. 38.99 − 29 =
  39. 39.29 + 19 =
  40. 40.53 + 9 =

Answer key

  1. 44
  2. 23
  3. 70
  4. 19
  5. 45
  6. 77
  7. 37
  8. 38
  9. 80
  10. 716
  11. 520
  12. 42
  13. 70
  14. 63
  15. 57
  16. 75
  17. 107
  18. 32
  19. 40
  20. 766
  21. 793
  22. 35
  23. 18
  24. 72
  25. 78
  26. 99
  27. 11
  28. 14
  29. 87
  30. 67
  31. 512
  32. 232
  33. 46
  34. 814
  35. 49
  36. 63
  37. 36
  38. 70
  39. 48
  40. 62

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