← 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 463 · 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 + … + 43 =
  2. 2.1 + 2 + 3 + … + 57 =
  3. 3.1 + 2 + 3 + … + 8 =
  4. 4.1 + 2 + 3 + … + 9 =
  5. 5.1 + 2 + 3 + … + 52 =
  6. 6.1 + 3 + 5 + … + 17 =
  7. 7.1 + 3 + 5 + … + 27 =
  8. 8.1 + 3 + 5 + … + 33 =
  9. 9.1 + 2 + 3 + … + 87 =
  10. 10.1 + 2 + 3 + … + 10 =
  11. 11.1 + 2 + 3 + … + 81 =
  12. 12.1 + 3 + 5 + … + 43 =
  13. 13.1 + 2 + 3 + … + 22 =
  14. 14.1 + 2 + 3 + … + 23 =
  15. 15.1 + 2 + 3 + … + 62 =
  16. 16.1 + 2 + 3 + … + 20 =
  17. 17.1 + 3 + 5 + … + 45 =
  18. 18.1 + 3 + 5 + … + 35 =
  19. 19.1 + 2 + 3 + … + 11 =
  20. 20.1 + 3 + 5 + … + 19 =
  21. 21.1 + 2 + 3 + … + 40 =
  22. 22.1 + 2 + 3 + … + 91 =
  23. 23.1 + 3 + 5 + … + 41 =
  24. 24.1 + 2 + 3 + … + 60 =
  25. 25.1 + 2 + 3 + … + 16 =
  26. 26.1 + 2 + 3 + … + 7 =
  27. 27.1 + 2 + 3 + … + 50 =
  28. 28.1 + 3 + 5 + … + 31 =
  29. 29.1 + 2 + 3 + … + 71 =
  30. 30.1 + 2 + 3 + … + 90 =
  31. 31.1 + 2 + 3 + … + 79 =
  32. 32.1 + 2 + 3 + … + 21 =
  33. 33.1 + 3 + 5 + … + 37 =
  34. 34.1 + 2 + 3 + … + 63 =
  35. 35.1 + 3 + 5 + … + 49 =
  36. 36.1 + 2 + 3 + … + 14 =
  37. 37.1 + 2 + 3 + … + 84 =
  38. 38.1 + 3 + 5 + … + 13 =
  39. 39.1 + 2 + 3 + … + 56 =
  40. 40.1 + 2 + 3 + … + 99 =

Answer key

  1. 946
  2. 1653
  3. 36
  4. 45
  5. 1378
  6. 81
  7. 196
  8. 289
  9. 3828
  10. 55
  11. 3321
  12. 484
  13. 253
  14. 276
  15. 1953
  16. 210
  17. 529
  18. 324
  19. 66
  20. 100
  21. 820
  22. 4186
  23. 441
  24. 1830
  25. 136
  26. 28
  27. 1275
  28. 256
  29. 2556
  30. 4095
  31. 3160
  32. 231
  33. 361
  34. 2016
  35. 625
  36. 105
  37. 3570
  38. 49
  39. 1596
  40. 4950

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