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Sum of 1 to 100 Worksheet

Maths tricks trick 8: Add 1 to 100 in seconds · Set 53 · 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 + … + 49 =
  2. 2.1 + 2 + 3 + … + 36 =
  3. 3.1 + 2 + 3 + … + 67 =
  4. 4.1 + 3 + 5 + … + 27 =
  5. 5.1 + 2 + 3 + … + 48 =
  6. 6.1 + 2 + 3 + … + 57 =
  7. 7.1 + 2 + 3 + … + 26 =
  8. 8.1 + 2 + 3 + … + 100 =
  9. 9.1 + 2 + 3 + … + 76 =
  10. 10.1 + 2 + 3 + … + 37 =
  11. 11.1 + 2 + 3 + … + 50 =
  12. 12.1 + 3 + 5 + … + 25 =
  13. 13.1 + 2 + 3 + … + 94 =
  14. 14.1 + 3 + 5 + … + 41 =
  15. 15.1 + 3 + 5 + … + 47 =
  16. 16.1 + 3 + 5 + … + 31 =
  17. 17.1 + 2 + 3 + … + 31 =
  18. 18.1 + 2 + 3 + … + 14 =
  19. 19.1 + 3 + 5 + … + 45 =
  20. 20.1 + 3 + 5 + … + 11 =
  21. 21.1 + 2 + 3 + … + 22 =
  22. 22.1 + 3 + 5 + … + 23 =
  23. 23.1 + 2 + 3 + … + 62 =
  24. 24.1 + 3 + 5 + … + 13 =
  25. 25.1 + 3 + 5 + … + 9 =
  26. 26.1 + 3 + 5 + … + 37 =
  27. 27.1 + 2 + 3 + … + 52 =
  28. 28.1 + 2 + 3 + … + 24 =
  29. 29.1 + 2 + 3 + … + 98 =
  30. 30.1 + 2 + 3 + … + 73 =
  31. 31.1 + 2 + 3 + … + 46 =
  32. 32.1 + 2 + 3 + … + 60 =
  33. 33.1 + 2 + 3 + … + 97 =
  34. 34.1 + 2 + 3 + … + 17 =
  35. 35.1 + 2 + 3 + … + 20 =
  36. 36.1 + 2 + 3 + … + 7 =
  37. 37.1 + 3 + 5 + … + 43 =
  38. 38.1 + 2 + 3 + … + 68 =
  39. 39.1 + 3 + 5 + … + 33 =
  40. 40.1 + 2 + 3 + … + 16 =

Answer key

  1. 625
  2. 666
  3. 2278
  4. 196
  5. 1176
  6. 1653
  7. 351
  8. 5050
  9. 2926
  10. 703
  11. 1275
  12. 169
  13. 4465
  14. 441
  15. 576
  16. 256
  17. 496
  18. 105
  19. 529
  20. 36
  21. 253
  22. 144
  23. 1953
  24. 49
  25. 25
  26. 361
  27. 1378
  28. 300
  29. 4851
  30. 2701
  31. 1081
  32. 1830
  33. 4753
  34. 153
  35. 210
  36. 28
  37. 484
  38. 2346
  39. 289
  40. 136

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