← 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 876 · 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 + … + 36 =
  2. 2.1 + 2 + 3 + … + 50 =
  3. 3.1 + 2 + 3 + … + 24 =
  4. 4.1 + 2 + 3 + … + 66 =
  5. 5.1 + 2 + 3 + … + 43 =
  6. 6.1 + 3 + 5 + … + 47 =
  7. 7.1 + 2 + 3 + … + 94 =
  8. 8.1 + 2 + 3 + … + 11 =
  9. 9.1 + 3 + 5 + … + 17 =
  10. 10.1 + 3 + 5 + … + 33 =
  11. 11.1 + 3 + 5 + … + 25 =
  12. 12.1 + 2 + 3 + … + 84 =
  13. 13.1 + 2 + 3 + … + 96 =
  14. 14.1 + 2 + 3 + … + 28 =
  15. 15.1 + 2 + 3 + … + 57 =
  16. 16.1 + 3 + 5 + … + 39 =
  17. 17.1 + 2 + 3 + … + 39 =
  18. 18.1 + 2 + 3 + … + 82 =
  19. 19.1 + 2 + 3 + … + 73 =
  20. 20.1 + 2 + 3 + … + 56 =
  21. 21.1 + 2 + 3 + … + 27 =
  22. 22.1 + 2 + 3 + … + 89 =
  23. 23.1 + 2 + 3 + … + 45 =
  24. 24.1 + 2 + 3 + … + 52 =
  25. 25.1 + 2 + 3 + … + 80 =
  26. 26.1 + 3 + 5 + … + 9 =
  27. 27.1 + 3 + 5 + … + 23 =
  28. 28.1 + 2 + 3 + … + 9 =
  29. 29.1 + 3 + 5 + … + 21 =
  30. 30.1 + 2 + 3 + … + 97 =
  31. 31.1 + 3 + 5 + … + 15 =
  32. 32.1 + 2 + 3 + … + 29 =
  33. 33.1 + 2 + 3 + … + 95 =
  34. 34.1 + 2 + 3 + … + 15 =
  35. 35.1 + 3 + 5 + … + 27 =
  36. 36.1 + 2 + 3 + … + 86 =
  37. 37.1 + 2 + 3 + … + 51 =
  38. 38.1 + 2 + 3 + … + 46 =
  39. 39.1 + 2 + 3 + … + 18 =
  40. 40.1 + 2 + 3 + … + 40 =

Answer key

  1. 666
  2. 1275
  3. 300
  4. 2211
  5. 946
  6. 576
  7. 4465
  8. 66
  9. 81
  10. 289
  11. 169
  12. 3570
  13. 4656
  14. 406
  15. 1653
  16. 400
  17. 780
  18. 3403
  19. 2701
  20. 1596
  21. 378
  22. 4005
  23. 1035
  24. 1378
  25. 3240
  26. 25
  27. 144
  28. 45
  29. 121
  30. 4753
  31. 64
  32. 435
  33. 4560
  34. 120
  35. 196
  36. 3741
  37. 1326
  38. 1081
  39. 171
  40. 820

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