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Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 834 · 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 + 7 + 15 + 22 + 37 + 59 + 96 + 155 + 251 + 406 =
  2. 2.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?
  3. 3.2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 + 348 =
  4. 4.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?
  5. 5.Leapfrog list (each number is the sum of the two before it): 7, 8, 15, 23, 38, 61, 99, 160, 259, 419. What is 11 × the 7th number?
  6. 6.Leapfrog list (each number is the sum of the two before it): 9, 4, 13, 17, 30, 47, 77, 124, 201, 325. What is 11 × the 7th number?
  7. 7.A leapfrog list starts 7, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  8. 8.A leapfrog list starts 3, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  9. 9.1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 =
  10. 10.Leapfrog list (each number is the sum of the two before it): 4, 4, 8, 12, 20, 32, 52, 84, 136, 220. What is 11 × the 7th number?
  11. 11.5 + 3 + 8 + 11 + 19 + 30 + 49 + 79 + 128 + 207 =
  12. 12.9 + 6 + 15 + 21 + 36 + 57 + 93 + 150 + 243 + 393 =
  13. 13.Leapfrog list (each number is the sum of the two before it): 3, 1, 4, 5, 9, 14, 23, 37, 60, 97. What is 11 × the 7th number?
  14. 14.8 + 1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 =
  15. 15.A leapfrog list starts 3, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  16. 16.3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 + 369 =
  17. 17.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?
  18. 18.4 + 9 + 13 + 22 + 35 + 57 + 92 + 149 + 241 + 390 =
  19. 19.1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 =
  20. 20.1 + 6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 + 225 =
  21. 21.3 + 7 + 10 + 17 + 27 + 44 + 71 + 115 + 186 + 301 =
  22. 22.A leapfrog list starts 5, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  23. 23.6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 + 398 =
  24. 24.A leapfrog list starts 9, 6 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 5, 4 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, 1, 7, 8, 15, 23, 38, 61, 99, 160. What is 11 × the 7th number?
  27. 27.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?
  28. 28.A leapfrog list starts 2, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  29. 29.A leapfrog list starts 7, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  30. 30.4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 + 178 + 288 =
  31. 31.7 + 5 + 12 + 17 + 29 + 46 + 75 + 121 + 196 + 317 =
  32. 32.Leapfrog list (each number is the sum of the two before it): 7, 3, 10, 13, 23, 36, 59, 95, 154, 249. What is 11 × the 7th number?
  33. 33.3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 + 233 =
  34. 34.1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 =
  35. 35.Leapfrog list (each number is the sum of the two before it): 2, 2, 4, 6, 10, 16, 26, 42, 68, 110. What is 11 × the 7th number?
  36. 36.Leapfrog list (each number is the sum of the two before it): 8, 7, 15, 22, 37, 59, 96, 155, 251, 406. What is 11 × the 7th number?
  37. 37.7 + 6 + 13 + 19 + 32 + 51 + 83 + 134 + 217 + 351 =
  38. 38.Leapfrog list (each number is the sum of the two before it): 2, 6, 8, 14, 22, 36, 58, 94, 152, 246. What is 11 × the 7th number?
  39. 39.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?
  40. 40.Leapfrog list (each number is the sum of the two before it): 2, 8, 10, 18, 28, 46, 74, 120, 194, 314. What is 11 × the 7th number?

Answer key

  1. 1056
  2. 924
  3. 902
  4. 583
  5. 1089
  6. 847
  7. 737
  8. 781
  9. 319
  10. 572
  11. 539
  12. 1023
  13. 253
  14. 528
  15. 869
  16. 957
  17. 231
  18. 1012
  19. 231
  20. 583
  21. 781
  22. 363
  23. 1034
  24. 1023
  25. 627
  26. 418
  27. 858
  28. 814
  29. 913
  30. 748
  31. 825
  32. 649
  33. 605
  34. 495
  35. 286
  36. 1056
  37. 913
  38. 638
  39. 1232
  40. 814

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