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Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 709 · 40 questions
TalentJR

The trick (Seventh times eleven): A leapfrog list: start with two numbers, then each number is the sum of the two before it, up to 10 numbers. Find the 7th number. Multiply it by 11 (the number with a 0 on the end, plus the number): that is the total of all 10.

NameDateTime takenScore ___ / 40
  1. 1.8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 + 474 =
  2. 2.Leapfrog list (each number is the sum of the two before it): 3, 3, 6, 9, 15, 24, 39, 63, 102, 165. What is 11 × the 7th number?
  3. 3.4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 + 199 + 322 =
  4. 4.3 + 7 + 10 + 17 + 27 + 44 + 71 + 115 + 186 + 301 =
  5. 5.A leapfrog list starts 2, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  6. 6.Leapfrog list (each number is the sum of the two before it): 1, 4, 5, 9, 14, 23, 37, 60, 97, 157. What is 11 × the 7th number?
  7. 7.5 + 2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 =
  8. 8.3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 + 369 =
  9. 9.A leapfrog list starts 8, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  10. 10.A leapfrog list starts 5, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  11. 11.A leapfrog list starts 1, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  12. 12.Leapfrog list (each number is the sum of the two before it): 7, 1, 8, 9, 17, 26, 43, 69, 112, 181. What is 11 × the 7th number?
  13. 13.2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 + 314 =
  14. 14.Leapfrog list (each number is the sum of the two before it): 4, 3, 7, 10, 17, 27, 44, 71, 115, 186. What is 11 × the 7th number?
  15. 15.7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 + 453 =
  16. 16.Leapfrog list (each number is the sum of the two before it): 1, 9, 10, 19, 29, 48, 77, 125, 202, 327. What is 11 × the 7th number?
  17. 17.Leapfrog list (each number is the sum of the two before it): 6, 7, 13, 20, 33, 53, 86, 139, 225, 364. What is 11 × the 7th number?
  18. 18.A leapfrog list starts 6, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  19. 19.A leapfrog list starts 2, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  20. 20.Leapfrog list (each number is the sum of the two before it): 9, 9, 18, 27, 45, 72, 117, 189, 306, 495. What is 11 × the 7th number?
  21. 21.8 + 4 + 12 + 16 + 28 + 44 + 72 + 116 + 188 + 304 =
  22. 22.5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 + 254 + 411 =
  23. 23.A leapfrog list starts 5, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  24. 24.Leapfrog list (each number is the sum of the two before it): 9, 1, 10, 11, 21, 32, 53, 85, 138, 223. What is 11 × the 7th number?
  25. 25.A leapfrog list starts 4, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  26. 26.Leapfrog list (each number is the sum of the two before it): 5, 7, 12, 19, 31, 50, 81, 131, 212, 343. What is 11 × the 7th number?
  27. 27.6 + 1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 =
  28. 28.Leapfrog list (each number is the sum of the two before it): 7, 2, 9, 11, 20, 31, 51, 82, 133, 215. What is 11 × the 7th number?
  29. 29.4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 + 356 =
  30. 30.Leapfrog list (each number is the sum of the two before it): 6, 1, 7, 8, 15, 23, 38, 61, 99, 160. What is 11 × the 7th number?
  31. 31.1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 =
  32. 32.A leapfrog list starts 6, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  33. 33.Leapfrog list (each number is the sum of the two before it): 5, 3, 8, 11, 19, 30, 49, 79, 128, 207. What is 11 × the 7th number?
  34. 34.A leapfrog list starts 5, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  35. 35.A leapfrog list starts 6, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  36. 36.A leapfrog list starts 8, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  37. 37.3 + 3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 =
  38. 38.2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 + 348 =
  39. 39.4 + 4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 =
  40. 40.Leapfrog list (each number is the sum of the two before it): 6, 2, 8, 10, 18, 28, 46, 74, 120, 194. What is 11 × the 7th number?

Answer key

  1. 1232
  2. 429
  3. 836
  4. 781
  5. 462
  6. 407
  7. 451
  8. 957
  9. 968
  10. 715
  11. 495
  12. 473
  13. 814
  14. 484
  15. 1177
  16. 847
  17. 946
  18. 770
  19. 726
  20. 1287
  21. 792
  22. 1067
  23. 803
  24. 583
  25. 308
  26. 891
  27. 418
  28. 561
  29. 924
  30. 418
  31. 231
  32. 418
  33. 539
  34. 979
  35. 506
  36. 1056
  37. 429
  38. 902
  39. 572
  40. 506

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