← 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 384 · 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. 1.33 − 19 =
  2. 2.38 + 9 =
  3. 3.60 + 19 =
  4. 4.76 − 19 =
  5. 5.59 − 29 =
  6. 6.60 + 9 =
  7. 7.508 + 99 =
  8. 8.73 − 19 =
  9. 9.29 − 9 =
  10. 10.31 + 19 =
  11. 11.424 + 99 =
  12. 12.27 + 19 =
  13. 13.69 + 9 =
  14. 14.31 − 9 =
  15. 15.28 + 9 =
  16. 16.473 − 99 =
  17. 17.24 − 9 =
  18. 18.86 − 9 =
  19. 19.805 − 99 =
  20. 20.67 − 9 =
  21. 21.56 + 19 =
  22. 22.23 + 29 =
  23. 23.600 − 99 =
  24. 24.399 − 99 =
  25. 25.494 + 99 =
  26. 26.21 + 19 =
  27. 27.34 − 19 =
  28. 28.76 − 29 =
  29. 29.75 + 19 =
  30. 30.312 − 99 =
  31. 31.46 + 9 =
  32. 32.79 + 9 =
  33. 33.36 + 9 =
  34. 34.19 + 9 =
  35. 35.30 + 9 =
  36. 36.16 + 29 =
  37. 37.70 + 9 =
  38. 38.51 + 9 =
  39. 39.37 + 19 =
  40. 40.46 − 9 =

Answer key

  1. 14
  2. 47
  3. 79
  4. 57
  5. 30
  6. 69
  7. 607
  8. 54
  9. 20
  10. 50
  11. 523
  12. 46
  13. 78
  14. 22
  15. 37
  16. 374
  17. 15
  18. 77
  19. 706
  20. 58
  21. 75
  22. 52
  23. 501
  24. 300
  25. 593
  26. 40
  27. 15
  28. 47
  29. 94
  30. 213
  31. 55
  32. 88
  33. 45
  34. 28
  35. 39
  36. 45
  37. 79
  38. 60
  39. 56
  40. 37

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