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Sum of 1 to 100 Worksheet

Maths tricks trick 8: Add 1 to 100 in seconds · Set 9 · 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 + … + 96 =
  2. 2.1 + 2 + 3 + … + 84 =
  3. 3.1 + 3 + 5 + … + 43 =
  4. 4.1 + 2 + 3 + … + 76 =
  5. 5.1 + 2 + 3 + … + 64 =
  6. 6.1 + 2 + 3 + … + 65 =
  7. 7.1 + 2 + 3 + … + 83 =
  8. 8.1 + 3 + 5 + … + 47 =
  9. 9.1 + 2 + 3 + … + 86 =
  10. 10.1 + 2 + 3 + … + 8 =
  11. 11.1 + 2 + 3 + … + 34 =
  12. 12.1 + 3 + 5 + … + 31 =
  13. 13.1 + 2 + 3 + … + 39 =
  14. 14.1 + 3 + 5 + … + 15 =
  15. 15.1 + 2 + 3 + … + 69 =
  16. 16.1 + 2 + 3 + … + 44 =
  17. 17.1 + 2 + 3 + … + 17 =
  18. 18.1 + 2 + 3 + … + 49 =
  19. 19.1 + 3 + 5 + … + 29 =
  20. 20.1 + 3 + 5 + … + 39 =
  21. 21.1 + 2 + 3 + … + 97 =
  22. 22.1 + 3 + 5 + … + 27 =
  23. 23.1 + 2 + 3 + … + 48 =
  24. 24.1 + 2 + 3 + … + 67 =
  25. 25.1 + 2 + 3 + … + 47 =
  26. 26.1 + 2 + 3 + … + 13 =
  27. 27.1 + 2 + 3 + … + 73 =
  28. 28.1 + 3 + 5 + … + 19 =
  29. 29.1 + 2 + 3 + … + 59 =
  30. 30.1 + 2 + 3 + … + 32 =
  31. 31.1 + 2 + 3 + … + 46 =
  32. 32.1 + 2 + 3 + … + 98 =
  33. 33.1 + 2 + 3 + … + 62 =
  34. 34.1 + 2 + 3 + … + 35 =
  35. 35.1 + 3 + 5 + … + 11 =
  36. 36.1 + 2 + 3 + … + 55 =
  37. 37.1 + 2 + 3 + … + 51 =
  38. 38.1 + 3 + 5 + … + 45 =
  39. 39.1 + 2 + 3 + … + 100 =
  40. 40.1 + 2 + 3 + … + 56 =

Answer key

  1. 4656
  2. 3570
  3. 484
  4. 2926
  5. 2080
  6. 2145
  7. 3486
  8. 576
  9. 3741
  10. 36
  11. 595
  12. 256
  13. 780
  14. 64
  15. 2415
  16. 990
  17. 153
  18. 1225
  19. 225
  20. 400
  21. 4753
  22. 196
  23. 1176
  24. 2278
  25. 1128
  26. 91
  27. 2701
  28. 100
  29. 1770
  30. 528
  31. 1081
  32. 4851
  33. 1953
  34. 630
  35. 36
  36. 1540
  37. 1326
  38. 529
  39. 5050
  40. 1596

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