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Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 973 · 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 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 + 453 =
  2. 2.1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 + 259 =
  3. 3.4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 + 199 + 322 =
  4. 4.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?
  5. 5.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?
  6. 6.6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 + 398 =
  7. 7.2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 =
  8. 8.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?
  9. 9.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?
  10. 10.4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 + 356 =
  11. 11.A leapfrog list starts 6, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  12. 12.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?
  13. 13.A leapfrog list starts 9, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  14. 14.7 + 7 + 14 + 21 + 35 + 56 + 91 + 147 + 238 + 385 =
  15. 15.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?
  16. 16.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?
  17. 17.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?
  18. 18.A leapfrog list starts 3, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  19. 19.9 + 9 + 18 + 27 + 45 + 72 + 117 + 189 + 306 + 495 =
  20. 20.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?
  21. 21.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?
  22. 22.9 + 6 + 15 + 21 + 36 + 57 + 93 + 150 + 243 + 393 =
  23. 23.2 + 2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 =
  24. 24.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?
  25. 25.6 + 2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 =
  26. 26.Leapfrog list (each number is the sum of the two before it): 2, 7, 9, 16, 25, 41, 66, 107, 173, 280. What is 11 × the 7th number?
  27. 27.A leapfrog list starts 7, 8 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): 3, 2, 5, 7, 12, 19, 31, 50, 81, 131. What is 11 × the 7th number?
  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.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.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?
  32. 32.A leapfrog list starts 9, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  33. 33.6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 + 267 + 432 =
  34. 34.6 + 6 + 12 + 18 + 30 + 48 + 78 + 126 + 204 + 330 =
  35. 35.A leapfrog list starts 4, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  36. 36.1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 =
  37. 37.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?
  38. 38.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?
  39. 39.Leapfrog list (each number is the sum of the two before it): 7, 5, 12, 17, 29, 46, 75, 121, 196, 317. What is 11 × the 7th number?
  40. 40.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?

Answer key

  1. 1177
  2. 671
  3. 836
  4. 704
  5. 605
  6. 1034
  7. 726
  8. 253
  9. 517
  10. 924
  11. 1034
  12. 979
  13. 1287
  14. 1001
  15. 407
  16. 671
  17. 1144
  18. 253
  19. 1287
  20. 198
  21. 198
  22. 1023
  23. 286
  24. 715
  25. 506
  26. 726
  27. 1089
  28. 341
  29. 913
  30. 561
  31. 858
  32. 759
  33. 1122
  34. 858
  35. 836
  36. 495
  37. 858
  38. 451
  39. 825
  40. 429

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