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Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 510 · 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. 1.4 + 2 + 6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 =
  2. 2.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?
  3. 3.4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 + 356 =
  4. 4.6 + 2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 =
  5. 5.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?
  6. 6.8 + 2 + 10 + 12 + 22 + 34 + 56 + 90 + 146 + 236 =
  7. 7.1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 =
  8. 8.5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 + 254 + 411 =
  9. 9.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?
  10. 10.2 + 1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 =
  11. 11.1 + 6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 + 225 =
  12. 12.A leapfrog list starts 6, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  13. 13.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?
  14. 14.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?
  15. 15.A leapfrog list starts 9, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  16. 16.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?
  17. 17.Leapfrog list (each number is the sum of the two before it): 9, 7, 16, 23, 39, 62, 101, 163, 264, 427. What is 11 × the 7th number?
  18. 18.Leapfrog list (each number is the sum of the two before it): 2, 1, 3, 4, 7, 11, 18, 29, 47, 76. What is 11 × the 7th number?
  19. 19.7 + 6 + 13 + 19 + 32 + 51 + 83 + 134 + 217 + 351 =
  20. 20.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?
  21. 21.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?
  22. 22.Leapfrog list (each number is the sum of the two before it): 5, 4, 9, 13, 22, 35, 57, 92, 149, 241. What is 11 × the 7th number?
  23. 23.5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 + 309 =
  24. 24.Leapfrog list (each number is the sum of the two before it): 2, 4, 6, 10, 16, 26, 42, 68, 110, 178. What is 11 × the 7th number?
  25. 25.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?
  26. 26.3 + 2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 =
  27. 27.A leapfrog list starts 7, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  28. 28.Leapfrog list (each number is the sum of the two before it): 8, 6, 14, 20, 34, 54, 88, 142, 230, 372. What is 11 × the 7th number?
  29. 29.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?
  30. 30.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?
  31. 31.2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 =
  32. 32.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?
  33. 33.7 + 5 + 12 + 17 + 29 + 46 + 75 + 121 + 196 + 317 =
  34. 34.A leapfrog list starts 1, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  35. 35.Leapfrog list (each number is the sum of the two before it): 9, 6, 15, 21, 36, 57, 93, 150, 243, 393. What is 11 × the 7th number?
  36. 36.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?
  37. 37.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?
  38. 38.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?
  39. 39.Leapfrog list (each number is the sum of the two before it): 5, 9, 14, 23, 37, 60, 97, 157, 254, 411. What is 11 × the 7th number?
  40. 40.8 + 8 + 16 + 24 + 40 + 64 + 104 + 168 + 272 + 440 =

Answer key

  1. 396
  2. 594
  3. 924
  4. 506
  5. 253
  6. 616
  7. 319
  8. 1067
  9. 495
  10. 198
  11. 583
  12. 858
  13. 583
  14. 814
  15. 1199
  16. 1287
  17. 1111
  18. 198
  19. 913
  20. 396
  21. 1056
  22. 627
  23. 803
  24. 462
  25. 869
  26. 341
  27. 473
  28. 968
  29. 1177
  30. 561
  31. 726
  32. 946
  33. 825
  34. 671
  35. 1023
  36. 396
  37. 572
  38. 484
  39. 1067
  40. 1144

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