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Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 385 · 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. 1.6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 + 225 + 364 =
  2. 2.2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 + 314 =
  3. 3.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?
  4. 4.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?
  5. 5.6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 + 398 =
  6. 6.Leapfrog list (each number is the sum of the two before it): 6, 5, 11, 16, 27, 43, 70, 113, 183, 296. What is 11 × the 7th number?
  7. 7.Leapfrog list (each number is the sum of the two before it): 1, 8, 9, 17, 26, 43, 69, 112, 181, 293. What is 11 × the 7th number?
  8. 8.5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 + 233 + 377 =
  9. 9.2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 =
  10. 10.A leapfrog list starts 1, 2 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 4, 9 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): 5, 2, 7, 9, 16, 25, 41, 66, 107, 173. What is 11 × the 7th number?
  13. 13.9 + 4 + 13 + 17 + 30 + 47 + 77 + 124 + 201 + 325 =
  14. 14.Leapfrog list (each number is the sum of the two before it): 1, 1, 2, 3, 5, 8, 13, 21, 34, 55. What is 11 × the 7th number?
  15. 15.2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 + 178 =
  16. 16.8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 + 474 =
  17. 17.7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 + 453 =
  18. 18.7 + 5 + 12 + 17 + 29 + 46 + 75 + 121 + 196 + 317 =
  19. 19.1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 + 259 =
  20. 20.2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 + 348 =
  21. 21.A leapfrog list starts 2, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  22. 22.A leapfrog list starts 6, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  23. 23.7 + 3 + 10 + 13 + 23 + 36 + 59 + 95 + 154 + 249 =
  24. 24.A leapfrog list starts 7, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  25. 25.A leapfrog list starts 1, 6 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): 6, 3, 9, 12, 21, 33, 54, 87, 141, 228. What is 11 × the 7th number?
  27. 27.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?
  28. 28.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?
  29. 29.8 + 3 + 11 + 14 + 25 + 39 + 64 + 103 + 167 + 270 =
  30. 30.A leapfrog list starts 6, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  31. 31.3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 + 267 =
  32. 32.2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 =
  33. 33.4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 + 356 =
  34. 34.Leapfrog list (each number is the sum of the two before it): 4, 2, 6, 8, 14, 22, 36, 58, 94, 152. What is 11 × the 7th number?
  35. 35.3 + 8 + 11 + 19 + 30 + 49 + 79 + 128 + 207 + 335 =
  36. 36.A leapfrog list starts 8, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  37. 37.Leapfrog list (each number is the sum of the two before it): 4, 8, 12, 20, 32, 52, 84, 136, 220, 356. What is 11 × the 7th number?
  38. 38.Leapfrog list (each number is the sum of the two before it): 7, 5, 12, 17, 29, 46, 75, 121, 196, 317. What is 11 × the 7th number?
  39. 39.2 + 1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 =
  40. 40.Leapfrog list (each number is the sum of the two before it): 6, 6, 12, 18, 30, 48, 78, 126, 204, 330. What is 11 × the 7th number?

Answer key

  1. 946
  2. 814
  3. 484
  4. 946
  5. 1034
  6. 770
  7. 759
  8. 979
  9. 374
  10. 231
  11. 1012
  12. 451
  13. 847
  14. 143
  15. 462
  16. 1232
  17. 1177
  18. 825
  19. 671
  20. 902
  21. 902
  22. 946
  23. 649
  24. 561
  25. 583
  26. 594
  27. 1287
  28. 968
  29. 704
  30. 594
  31. 693
  32. 726
  33. 924
  34. 396
  35. 869
  36. 704
  37. 924
  38. 825
  39. 198
  40. 858

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