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Sum of 1 to 100 Worksheet

Maths tricks trick 8: Add 1 to 100 in seconds · Set 509 · 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 + … + 94 =
  3. 3.1 + 3 + 5 + … + 13 =
  4. 4.1 + 2 + 3 + … + 91 =
  5. 5.1 + 3 + 5 + … + 25 =
  6. 6.1 + 3 + 5 + … + 35 =
  7. 7.1 + 2 + 3 + … + 50 =
  8. 8.1 + 3 + 5 + … + 15 =
  9. 9.1 + 2 + 3 + … + 72 =
  10. 10.1 + 2 + 3 + … + 16 =
  11. 11.1 + 3 + 5 + … + 49 =
  12. 12.1 + 2 + 3 + … + 48 =
  13. 13.1 + 3 + 5 + … + 43 =
  14. 14.1 + 2 + 3 + … + 32 =
  15. 15.1 + 2 + 3 + … + 85 =
  16. 16.1 + 2 + 3 + … + 41 =
  17. 17.1 + 2 + 3 + … + 14 =
  18. 18.1 + 2 + 3 + … + 70 =
  19. 19.1 + 2 + 3 + … + 27 =
  20. 20.1 + 2 + 3 + … + 77 =
  21. 21.1 + 2 + 3 + … + 29 =
  22. 22.1 + 2 + 3 + … + 57 =
  23. 23.1 + 3 + 5 + … + 27 =
  24. 24.1 + 2 + 3 + … + 59 =
  25. 25.1 + 2 + 3 + … + 56 =
  26. 26.1 + 2 + 3 + … + 68 =
  27. 27.1 + 2 + 3 + … + 36 =
  28. 28.1 + 3 + 5 + … + 39 =
  29. 29.1 + 2 + 3 + … + 97 =
  30. 30.1 + 2 + 3 + … + 10 =
  31. 31.1 + 2 + 3 + … + 62 =
  32. 32.1 + 2 + 3 + … + 17 =
  33. 33.1 + 2 + 3 + … + 35 =
  34. 34.1 + 2 + 3 + … + 63 =
  35. 35.1 + 3 + 5 + … + 33 =
  36. 36.1 + 2 + 3 + … + 52 =
  37. 37.1 + 2 + 3 + … + 61 =
  38. 38.1 + 2 + 3 + … + 26 =
  39. 39.1 + 3 + 5 + … + 9 =
  40. 40.1 + 2 + 3 + … + 55 =

Answer key

  1. 946
  2. 4465
  3. 49
  4. 4186
  5. 169
  6. 324
  7. 1275
  8. 64
  9. 2628
  10. 136
  11. 625
  12. 1176
  13. 484
  14. 528
  15. 3655
  16. 861
  17. 105
  18. 2485
  19. 378
  20. 3003
  21. 435
  22. 1653
  23. 196
  24. 1770
  25. 1596
  26. 2346
  27. 666
  28. 400
  29. 4753
  30. 55
  31. 1953
  32. 153
  33. 630
  34. 2016
  35. 289
  36. 1378
  37. 1891
  38. 351
  39. 25
  40. 1540

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