← 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 519 · 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 + 2 + 3 + … + 63 =
  2. 2.1 + 2 + 3 + … + 41 =
  3. 3.1 + 2 + 3 + … + 24 =
  4. 4.1 + 3 + 5 + … + 25 =
  5. 5.1 + 3 + 5 + … + 37 =
  6. 6.1 + 2 + 3 + … + 83 =
  7. 7.1 + 2 + 3 + … + 33 =
  8. 8.1 + 2 + 3 + … + 60 =
  9. 9.1 + 3 + 5 + … + 31 =
  10. 10.1 + 3 + 5 + … + 49 =
  11. 11.1 + 3 + 5 + … + 29 =
  12. 12.1 + 2 + 3 + … + 51 =
  13. 13.1 + 3 + 5 + … + 43 =
  14. 14.1 + 2 + 3 + … + 76 =
  15. 15.1 + 2 + 3 + … + 14 =
  16. 16.1 + 2 + 3 + … + 32 =
  17. 17.1 + 2 + 3 + … + 58 =
  18. 18.1 + 2 + 3 + … + 89 =
  19. 19.1 + 3 + 5 + … + 17 =
  20. 20.1 + 3 + 5 + … + 19 =
  21. 21.1 + 2 + 3 + … + 16 =
  22. 22.1 + 2 + 3 + … + 57 =
  23. 23.1 + 2 + 3 + … + 46 =
  24. 24.1 + 3 + 5 + … + 11 =
  25. 25.1 + 3 + 5 + … + 21 =
  26. 26.1 + 3 + 5 + … + 9 =
  27. 27.1 + 3 + 5 + … + 27 =
  28. 28.1 + 2 + 3 + … + 90 =
  29. 29.1 + 2 + 3 + … + 94 =
  30. 30.1 + 3 + 5 + … + 23 =
  31. 31.1 + 2 + 3 + … + 59 =
  32. 32.1 + 2 + 3 + … + 36 =
  33. 33.1 + 2 + 3 + … + 80 =
  34. 34.1 + 2 + 3 + … + 30 =
  35. 35.1 + 3 + 5 + … + 45 =
  36. 36.1 + 2 + 3 + … + 37 =
  37. 37.1 + 2 + 3 + … + 95 =
  38. 38.1 + 2 + 3 + … + 19 =
  39. 39.1 + 2 + 3 + … + 43 =
  40. 40.1 + 2 + 3 + … + 18 =

Answer key

  1. 2016
  2. 861
  3. 300
  4. 169
  5. 361
  6. 3486
  7. 561
  8. 1830
  9. 256
  10. 625
  11. 225
  12. 1326
  13. 484
  14. 2926
  15. 105
  16. 528
  17. 1711
  18. 4005
  19. 81
  20. 100
  21. 136
  22. 1653
  23. 1081
  24. 36
  25. 121
  26. 25
  27. 196
  28. 4095
  29. 4465
  30. 144
  31. 1770
  32. 666
  33. 3240
  34. 465
  35. 529
  36. 703
  37. 4560
  38. 190
  39. 946
  40. 171

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