← Add 1 to 100 in seconds lesson New set →

Sum of 1 to 100 Worksheet

Maths tricks trick 8: Add 1 to 100 in seconds · Set 676 · 40 questions
TalentJR

The trick (Pairs): Pair the first and last numbers: each pair adds to n + 1. Count the pairs — or multiply n × (n + 1) and halve it. Odd numbers 1 + 3 + 5 + …: count them and multiply that count by itself.

NameDateTime takenScore ___ / 40
  1. 1.1 + 3 + 5 + … + 47 =
  2. 2.1 + 2 + 3 + … + 17 =
  3. 3.1 + 2 + 3 + … + 69 =
  4. 4.1 + 3 + 5 + … + 27 =
  5. 5.1 + 2 + 3 + … + 12 =
  6. 6.1 + 3 + 5 + … + 17 =
  7. 7.1 + 3 + 5 + … + 41 =
  8. 8.1 + 2 + 3 + … + 33 =
  9. 9.1 + 3 + 5 + … + 45 =
  10. 10.1 + 2 + 3 + … + 20 =
  11. 11.1 + 3 + 5 + … + 39 =
  12. 12.1 + 3 + 5 + … + 11 =
  13. 13.1 + 3 + 5 + … + 23 =
  14. 14.1 + 2 + 3 + … + 11 =
  15. 15.1 + 3 + 5 + … + 49 =
  16. 16.1 + 3 + 5 + … + 25 =
  17. 17.1 + 3 + 5 + … + 19 =
  18. 18.1 + 2 + 3 + … + 44 =
  19. 19.1 + 2 + 3 + … + 51 =
  20. 20.1 + 3 + 5 + … + 9 =
  21. 21.1 + 3 + 5 + … + 13 =
  22. 22.1 + 2 + 3 + … + 75 =
  23. 23.1 + 2 + 3 + … + 40 =
  24. 24.1 + 2 + 3 + … + 63 =
  25. 25.1 + 2 + 3 + … + 73 =
  26. 26.1 + 2 + 3 + … + 77 =
  27. 27.1 + 2 + 3 + … + 50 =
  28. 28.1 + 2 + 3 + … + 38 =
  29. 29.1 + 2 + 3 + … + 27 =
  30. 30.1 + 2 + 3 + … + 56 =
  31. 31.1 + 2 + 3 + … + 85 =
  32. 32.1 + 2 + 3 + … + 43 =
  33. 33.1 + 2 + 3 + … + 28 =
  34. 34.1 + 2 + 3 + … + 76 =
  35. 35.1 + 2 + 3 + … + 84 =
  36. 36.1 + 3 + 5 + … + 33 =
  37. 37.1 + 2 + 3 + … + 7 =
  38. 38.1 + 2 + 3 + … + 54 =
  39. 39.1 + 2 + 3 + … + 78 =
  40. 40.1 + 2 + 3 + … + 93 =

Answer key

  1. 576
  2. 153
  3. 2415
  4. 196
  5. 78
  6. 81
  7. 441
  8. 561
  9. 529
  10. 210
  11. 400
  12. 36
  13. 144
  14. 66
  15. 625
  16. 169
  17. 100
  18. 990
  19. 1326
  20. 25
  21. 49
  22. 2850
  23. 820
  24. 2016
  25. 2701
  26. 3003
  27. 1275
  28. 741
  29. 378
  30. 1596
  31. 3655
  32. 946
  33. 406
  34. 2926
  35. 3570
  36. 289
  37. 28
  38. 1485
  39. 3081
  40. 4371

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