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Sum of 1 to 100 Worksheet

Maths tricks trick 8: Add 1 to 100 in seconds · Set 550 · 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 + 3 + 5 + … + 45 =
  2. 2.1 + 2 + 3 + … + 67 =
  3. 3.1 + 2 + 3 + … + 71 =
  4. 4.1 + 2 + 3 + … + 64 =
  5. 5.1 + 2 + 3 + … + 35 =
  6. 6.1 + 2 + 3 + … + 13 =
  7. 7.1 + 2 + 3 + … + 49 =
  8. 8.1 + 3 + 5 + … + 41 =
  9. 9.1 + 2 + 3 + … + 24 =
  10. 10.1 + 2 + 3 + … + 7 =
  11. 11.1 + 2 + 3 + … + 14 =
  12. 12.1 + 2 + 3 + … + 41 =
  13. 13.1 + 3 + 5 + … + 43 =
  14. 14.1 + 2 + 3 + … + 52 =
  15. 15.1 + 2 + 3 + … + 86 =
  16. 16.1 + 3 + 5 + … + 39 =
  17. 17.1 + 3 + 5 + … + 37 =
  18. 18.1 + 2 + 3 + … + 27 =
  19. 19.1 + 2 + 3 + … + 16 =
  20. 20.1 + 3 + 5 + … + 27 =
  21. 21.1 + 2 + 3 + … + 69 =
  22. 22.1 + 3 + 5 + … + 23 =
  23. 23.1 + 2 + 3 + … + 46 =
  24. 24.1 + 2 + 3 + … + 91 =
  25. 25.1 + 2 + 3 + … + 18 =
  26. 26.1 + 2 + 3 + … + 95 =
  27. 27.1 + 2 + 3 + … + 45 =
  28. 28.1 + 3 + 5 + … + 17 =
  29. 29.1 + 2 + 3 + … + 9 =
  30. 30.1 + 2 + 3 + … + 31 =
  31. 31.1 + 2 + 3 + … + 98 =
  32. 32.1 + 2 + 3 + … + 17 =
  33. 33.1 + 2 + 3 + … + 77 =
  34. 34.1 + 2 + 3 + … + 29 =
  35. 35.1 + 2 + 3 + … + 10 =
  36. 36.1 + 2 + 3 + … + 38 =
  37. 37.1 + 2 + 3 + … + 82 =
  38. 38.1 + 2 + 3 + … + 44 =
  39. 39.1 + 2 + 3 + … + 58 =
  40. 40.1 + 3 + 5 + … + 19 =

Answer key

  1. 529
  2. 2278
  3. 2556
  4. 2080
  5. 630
  6. 91
  7. 1225
  8. 441
  9. 300
  10. 28
  11. 105
  12. 861
  13. 484
  14. 1378
  15. 3741
  16. 400
  17. 361
  18. 378
  19. 136
  20. 196
  21. 2415
  22. 144
  23. 1081
  24. 4186
  25. 171
  26. 4560
  27. 1035
  28. 81
  29. 45
  30. 496
  31. 4851
  32. 153
  33. 3003
  34. 435
  35. 55
  36. 741
  37. 3403
  38. 990
  39. 1711
  40. 100

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