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Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 256 · 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, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  2. 2.6 + 1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 =
  3. 3.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?
  4. 4.5 + 3 + 8 + 11 + 19 + 30 + 49 + 79 + 128 + 207 =
  5. 5.A leapfrog list starts 9, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  6. 6.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?
  7. 7.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?
  8. 8.Leapfrog list (each number is the sum of the two before it): 8, 8, 16, 24, 40, 64, 104, 168, 272, 440. What is 11 × the 7th number?
  9. 9.9 + 6 + 15 + 21 + 36 + 57 + 93 + 150 + 243 + 393 =
  10. 10.4 + 4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 =
  11. 11.8 + 1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 =
  12. 12.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?
  13. 13.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?
  14. 14.5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 + 233 + 377 =
  15. 15.A leapfrog list starts 2, 4 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, 7, 16, 23, 39, 62, 101, 163, 264, 427. What is 11 × the 7th number?
  17. 17.3 + 1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 =
  18. 18.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?
  19. 19.Leapfrog list (each number is the sum of the two before it): 5, 1, 6, 7, 13, 20, 33, 53, 86, 139. What is 11 × the 7th number?
  20. 20.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?
  21. 21.A leapfrog list starts 1, 1 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 5, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  23. 23.4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 + 356 =
  24. 24.Leapfrog list (each number is the sum of the two before it): 1, 7, 8, 15, 23, 38, 61, 99, 160, 259. What is 11 × the 7th number?
  25. 25.Leapfrog list (each number is the sum of the two before it): 3, 2, 5, 7, 12, 19, 31, 50, 81, 131. What is 11 × the 7th number?
  26. 26.2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 =
  27. 27.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?
  28. 28.A leapfrog list starts 8, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  29. 29.Leapfrog list (each number is the sum of the two before it): 7, 6, 13, 19, 32, 51, 83, 134, 217, 351. What is 11 × the 7th number?
  30. 30.2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 =
  31. 31.5 + 5 + 10 + 15 + 25 + 40 + 65 + 105 + 170 + 275 =
  32. 32.A leapfrog list starts 2, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  33. 33.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?
  34. 34.6 + 6 + 12 + 18 + 30 + 48 + 78 + 126 + 204 + 330 =
  35. 35.A leapfrog list starts 9, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  36. 36.A leapfrog list starts 8, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  37. 37.7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 + 453 =
  38. 38.2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 + 178 =
  39. 39.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?
  40. 40.4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 + 178 + 288 =

Answer key

  1. 704
  2. 418
  3. 1177
  4. 539
  5. 583
  6. 396
  7. 781
  8. 1144
  9. 1023
  10. 572
  11. 528
  12. 429
  13. 858
  14. 979
  15. 462
  16. 1111
  17. 253
  18. 825
  19. 363
  20. 1001
  21. 143
  22. 891
  23. 924
  24. 671
  25. 341
  26. 550
  27. 253
  28. 1056
  29. 913
  30. 726
  31. 715
  32. 374
  33. 792
  34. 858
  35. 671
  36. 616
  37. 1177
  38. 462
  39. 638
  40. 748

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