← 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 68 · 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 + … + 10 =
  2. 2.1 + 2 + 3 + … + 92 =
  3. 3.1 + 2 + 3 + … + 31 =
  4. 4.1 + 3 + 5 + … + 37 =
  5. 5.1 + 3 + 5 + … + 45 =
  6. 6.1 + 2 + 3 + … + 17 =
  7. 7.1 + 2 + 3 + … + 60 =
  8. 8.1 + 2 + 3 + … + 62 =
  9. 9.1 + 2 + 3 + … + 97 =
  10. 10.1 + 3 + 5 + … + 33 =
  11. 11.1 + 2 + 3 + … + 18 =
  12. 12.1 + 3 + 5 + … + 39 =
  13. 13.1 + 3 + 5 + … + 43 =
  14. 14.1 + 2 + 3 + … + 84 =
  15. 15.1 + 3 + 5 + … + 27 =
  16. 16.1 + 2 + 3 + … + 57 =
  17. 17.1 + 3 + 5 + … + 13 =
  18. 18.1 + 2 + 3 + … + 49 =
  19. 19.1 + 2 + 3 + … + 100 =
  20. 20.1 + 3 + 5 + … + 35 =
  21. 21.1 + 2 + 3 + … + 30 =
  22. 22.1 + 2 + 3 + … + 58 =
  23. 23.1 + 3 + 5 + … + 17 =
  24. 24.1 + 2 + 3 + … + 45 =
  25. 25.1 + 2 + 3 + … + 15 =
  26. 26.1 + 2 + 3 + … + 90 =
  27. 27.1 + 2 + 3 + … + 6 =
  28. 28.1 + 2 + 3 + … + 81 =
  29. 29.1 + 2 + 3 + … + 32 =
  30. 30.1 + 3 + 5 + … + 9 =
  31. 31.1 + 2 + 3 + … + 52 =
  32. 32.1 + 2 + 3 + … + 24 =
  33. 33.1 + 2 + 3 + … + 16 =
  34. 34.1 + 2 + 3 + … + 13 =
  35. 35.1 + 2 + 3 + … + 66 =
  36. 36.1 + 2 + 3 + … + 41 =
  37. 37.1 + 2 + 3 + … + 63 =
  38. 38.1 + 2 + 3 + … + 85 =
  39. 39.1 + 2 + 3 + … + 27 =
  40. 40.1 + 3 + 5 + … + 31 =

Answer key

  1. 55
  2. 4278
  3. 496
  4. 361
  5. 529
  6. 153
  7. 1830
  8. 1953
  9. 4753
  10. 289
  11. 171
  12. 400
  13. 484
  14. 3570
  15. 196
  16. 1653
  17. 49
  18. 1225
  19. 5050
  20. 324
  21. 465
  22. 1711
  23. 81
  24. 1035
  25. 120
  26. 4095
  27. 21
  28. 3321
  29. 528
  30. 25
  31. 1378
  32. 300
  33. 136
  34. 91
  35. 2211
  36. 861
  37. 2016
  38. 3655
  39. 378
  40. 256

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