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Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 411 · 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.A leapfrog list starts 8, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  2. 2.A leapfrog list starts 2, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  3. 3.7 + 3 + 10 + 13 + 23 + 36 + 59 + 95 + 154 + 249 =
  4. 4.6 + 4 + 10 + 14 + 24 + 38 + 62 + 100 + 162 + 262 =
  5. 5.3 + 8 + 11 + 19 + 30 + 49 + 79 + 128 + 207 + 335 =
  6. 6.2 + 2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 =
  7. 7.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?
  8. 8.6 + 3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 =
  9. 9.6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 + 398 =
  10. 10.A leapfrog list starts 7, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  11. 11.Leapfrog list (each number is the sum of the two before it): 9, 5, 14, 19, 33, 52, 85, 137, 222, 359. What is 11 × the 7th number?
  12. 12.Leapfrog list (each number is the sum of the two before it): 1, 5, 6, 11, 17, 28, 45, 73, 118, 191. What is 11 × the 7th number?
  13. 13.A leapfrog list starts 4, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  14. 14.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?
  15. 15.Leapfrog list (each number is the sum of the two before it): 8, 9, 17, 26, 43, 69, 112, 181, 293, 474. What is 11 × the 7th number?
  16. 16.7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 + 259 + 419 =
  17. 17.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?
  18. 18.1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 =
  19. 19.8 + 4 + 12 + 16 + 28 + 44 + 72 + 116 + 188 + 304 =
  20. 20.Leapfrog list (each number is the sum of the two before it): 5, 6, 11, 17, 28, 45, 73, 118, 191, 309. What is 11 × the 7th number?
  21. 21.4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 + 356 =
  22. 22.2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 + 314 =
  23. 23.Leapfrog list (each number is the sum of the two before it): 8, 2, 10, 12, 22, 34, 56, 90, 146, 236. What is 11 × the 7th number?
  24. 24.A leapfrog list starts 7, 5 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 9, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  26. 26.A leapfrog list starts 5, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  27. 27.3 + 2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 =
  28. 28.7 + 5 + 12 + 17 + 29 + 46 + 75 + 121 + 196 + 317 =
  29. 29.Leapfrog list (each number is the sum of the two before it): 5, 8, 13, 21, 34, 55, 89, 144, 233, 377. What is 11 × the 7th number?
  30. 30.2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 + 178 =
  31. 31.Leapfrog list (each number is the sum of the two before it): 3, 9, 12, 21, 33, 54, 87, 141, 228, 369. What is 11 × the 7th number?
  32. 32.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?
  33. 33.7 + 1 + 8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 =
  34. 34.1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 + 327 =
  35. 35.2 + 1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 =
  36. 36.9 + 8 + 17 + 25 + 42 + 67 + 109 + 176 + 285 + 461 =
  37. 37.A leapfrog list starts 3, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  38. 38.Leapfrog list (each number is the sum of the two before it): 3, 4, 7, 11, 18, 29, 47, 76, 123, 199. What is 11 × the 7th number?
  39. 39.Leapfrog list (each number is the sum of the two before it): 7, 9, 16, 25, 41, 66, 107, 173, 280, 453. What is 11 × the 7th number?
  40. 40.A leapfrog list starts 7, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?

Answer key

  1. 792
  2. 286
  3. 649
  4. 682
  5. 869
  6. 286
  7. 495
  8. 594
  9. 1034
  10. 1177
  11. 935
  12. 495
  13. 396
  14. 561
  15. 1232
  16. 1089
  17. 506
  18. 319
  19. 792
  20. 803
  21. 924
  22. 814
  23. 616
  24. 825
  25. 847
  26. 451
  27. 341
  28. 825
  29. 979
  30. 462
  31. 957
  32. 539
  33. 473
  34. 847
  35. 198
  36. 1199
  37. 605
  38. 517
  39. 1177
  40. 649

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