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Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 252 · 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. 1.7 + 5 + 12 + 17 + 29 + 46 + 75 + 121 + 196 + 317 =
  2. 2.8 + 7 + 15 + 22 + 37 + 59 + 96 + 155 + 251 + 406 =
  3. 3.7 + 1 + 8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 =
  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.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?
  6. 6.9 + 2 + 11 + 13 + 24 + 37 + 61 + 98 + 159 + 257 =
  7. 7.1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 =
  8. 8.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?
  9. 9.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?
  10. 10.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?
  11. 11.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?
  12. 12.A leapfrog list starts 3, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  13. 13.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?
  14. 14.9 + 1 + 10 + 11 + 21 + 32 + 53 + 85 + 138 + 223 =
  15. 15.Leapfrog list (each number is the sum of the two before it): 2, 9, 11, 20, 31, 51, 82, 133, 215, 348. What is 11 × the 7th number?
  16. 16.A leapfrog list starts 3, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  17. 17.Leapfrog list (each number is the sum of the two before it): 3, 5, 8, 13, 21, 34, 55, 89, 144, 233. What is 11 × the 7th number?
  18. 18.Leapfrog list (each number is the sum of the two before it): 1, 6, 7, 13, 20, 33, 53, 86, 139, 225. What is 11 × the 7th number?
  19. 19.A leapfrog list starts 4, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  20. 20.4 + 3 + 7 + 10 + 17 + 27 + 44 + 71 + 115 + 186 =
  21. 21.8 + 1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 =
  22. 22.A leapfrog list starts 9, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  23. 23.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?
  24. 24.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?
  25. 25.Leapfrog list (each number is the sum of the two before it): 9, 3, 12, 15, 27, 42, 69, 111, 180, 291. What is 11 × the 7th number?
  26. 26.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?
  27. 27.Leapfrog list (each number is the sum of the two before it): 4, 1, 5, 6, 11, 17, 28, 45, 73, 118. What is 11 × the 7th number?
  28. 28.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?
  29. 29.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?
  30. 30.A leapfrog list starts 1, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  31. 31.A leapfrog list starts 2, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  32. 32.5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 + 233 + 377 =
  33. 33.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?
  34. 34.Leapfrog list (each number is the sum of the two before it): 7, 7, 14, 21, 35, 56, 91, 147, 238, 385. What is 11 × the 7th number?
  35. 35.2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 + 178 =
  36. 36.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?
  37. 37.6 + 2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 =
  38. 38.Leapfrog list (each number is the sum of the two before it): 4, 7, 11, 18, 29, 47, 76, 123, 199, 322. What is 11 × the 7th number?
  39. 39.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?
  40. 40.8 + 3 + 11 + 14 + 25 + 39 + 64 + 103 + 167 + 270 =

Answer key

  1. 825
  2. 1056
  3. 473
  4. 946
  5. 803
  6. 671
  7. 319
  8. 913
  9. 605
  10. 396
  11. 308
  12. 517
  13. 407
  14. 583
  15. 902
  16. 429
  17. 605
  18. 583
  19. 484
  20. 484
  21. 528
  22. 1111
  23. 1287
  24. 429
  25. 759
  26. 286
  27. 308
  28. 803
  29. 418
  30. 407
  31. 198
  32. 979
  33. 253
  34. 1001
  35. 462
  36. 715
  37. 506
  38. 836
  39. 649
  40. 704

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