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Sum of 1 to 100 Worksheet

Maths tricks trick 8: Add 1 to 100 in seconds · Set 48 · 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 + … + 25 =
  2. 2.1 + 2 + 3 + … + 95 =
  3. 3.1 + 3 + 5 + … + 23 =
  4. 4.1 + 3 + 5 + … + 35 =
  5. 5.1 + 2 + 3 + … + 6 =
  6. 6.1 + 2 + 3 + … + 81 =
  7. 7.1 + 3 + 5 + … + 19 =
  8. 8.1 + 3 + 5 + … + 9 =
  9. 9.1 + 2 + 3 + … + 66 =
  10. 10.1 + 2 + 3 + … + 10 =
  11. 11.1 + 2 + 3 + … + 63 =
  12. 12.1 + 2 + 3 + … + 87 =
  13. 13.1 + 3 + 5 + … + 29 =
  14. 14.1 + 3 + 5 + … + 15 =
  15. 15.1 + 2 + 3 + … + 72 =
  16. 16.1 + 2 + 3 + … + 91 =
  17. 17.1 + 2 + 3 + … + 46 =
  18. 18.1 + 2 + 3 + … + 93 =
  19. 19.1 + 3 + 5 + … + 27 =
  20. 20.1 + 2 + 3 + … + 67 =
  21. 21.1 + 3 + 5 + … + 45 =
  22. 22.1 + 2 + 3 + … + 65 =
  23. 23.1 + 2 + 3 + … + 59 =
  24. 24.1 + 2 + 3 + … + 21 =
  25. 25.1 + 2 + 3 + … + 97 =
  26. 26.1 + 3 + 5 + … + 11 =
  27. 27.1 + 2 + 3 + … + 11 =
  28. 28.1 + 2 + 3 + … + 90 =
  29. 29.1 + 2 + 3 + … + 33 =
  30. 30.1 + 2 + 3 + … + 18 =
  31. 31.1 + 3 + 5 + … + 21 =
  32. 32.1 + 2 + 3 + … + 84 =
  33. 33.1 + 2 + 3 + … + 12 =
  34. 34.1 + 3 + 5 + … + 43 =
  35. 35.1 + 2 + 3 + … + 62 =
  36. 36.1 + 2 + 3 + … + 25 =
  37. 37.1 + 2 + 3 + … + 13 =
  38. 38.1 + 2 + 3 + … + 16 =
  39. 39.1 + 3 + 5 + … + 49 =
  40. 40.1 + 2 + 3 + … + 86 =

Answer key

  1. 169
  2. 4560
  3. 144
  4. 324
  5. 21
  6. 3321
  7. 100
  8. 25
  9. 2211
  10. 55
  11. 2016
  12. 3828
  13. 225
  14. 64
  15. 2628
  16. 4186
  17. 1081
  18. 4371
  19. 196
  20. 2278
  21. 529
  22. 2145
  23. 1770
  24. 231
  25. 4753
  26. 36
  27. 66
  28. 4095
  29. 561
  30. 171
  31. 121
  32. 3570
  33. 78
  34. 484
  35. 1953
  36. 325
  37. 91
  38. 136
  39. 625
  40. 3741

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