← 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 726 · 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 + … + 94 =
  2. 2.1 + 3 + 5 + … + 39 =
  3. 3.1 + 2 + 3 + … + 68 =
  4. 4.1 + 2 + 3 + … + 33 =
  5. 5.1 + 3 + 5 + … + 13 =
  6. 6.1 + 2 + 3 + … + 99 =
  7. 7.1 + 2 + 3 + … + 30 =
  8. 8.1 + 3 + 5 + … + 49 =
  9. 9.1 + 3 + 5 + … + 47 =
  10. 10.1 + 2 + 3 + … + 40 =
  11. 11.1 + 2 + 3 + … + 37 =
  12. 12.1 + 2 + 3 + … + 92 =
  13. 13.1 + 2 + 3 + … + 22 =
  14. 14.1 + 2 + 3 + … + 9 =
  15. 15.1 + 2 + 3 + … + 34 =
  16. 16.1 + 2 + 3 + … + 63 =
  17. 17.1 + 3 + 5 + … + 23 =
  18. 18.1 + 3 + 5 + … + 17 =
  19. 19.1 + 2 + 3 + … + 70 =
  20. 20.1 + 3 + 5 + … + 31 =
  21. 21.1 + 2 + 3 + … + 50 =
  22. 22.1 + 2 + 3 + … + 73 =
  23. 23.1 + 3 + 5 + … + 9 =
  24. 24.1 + 3 + 5 + … + 19 =
  25. 25.1 + 2 + 3 + … + 78 =
  26. 26.1 + 2 + 3 + … + 24 =
  27. 27.1 + 2 + 3 + … + 28 =
  28. 28.1 + 2 + 3 + … + 98 =
  29. 29.1 + 2 + 3 + … + 46 =
  30. 30.1 + 2 + 3 + … + 8 =
  31. 31.1 + 3 + 5 + … + 15 =
  32. 32.1 + 2 + 3 + … + 27 =
  33. 33.1 + 2 + 3 + … + 39 =
  34. 34.1 + 2 + 3 + … + 67 =
  35. 35.1 + 2 + 3 + … + 51 =
  36. 36.1 + 2 + 3 + … + 53 =
  37. 37.1 + 2 + 3 + … + 12 =
  38. 38.1 + 2 + 3 + … + 57 =
  39. 39.1 + 2 + 3 + … + 10 =
  40. 40.1 + 2 + 3 + … + 59 =

Answer key

  1. 4465
  2. 400
  3. 2346
  4. 561
  5. 49
  6. 4950
  7. 465
  8. 625
  9. 576
  10. 820
  11. 703
  12. 4278
  13. 253
  14. 45
  15. 595
  16. 2016
  17. 144
  18. 81
  19. 2485
  20. 256
  21. 1275
  22. 2701
  23. 25
  24. 100
  25. 3081
  26. 300
  27. 406
  28. 4851
  29. 1081
  30. 36
  31. 64
  32. 378
  33. 780
  34. 2278
  35. 1326
  36. 1431
  37. 78
  38. 1653
  39. 55
  40. 1770

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