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Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 301 · 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.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?
  2. 2.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?
  3. 3.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?
  4. 4.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?
  5. 5.3 + 3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 =
  6. 6.9 + 4 + 13 + 17 + 30 + 47 + 77 + 124 + 201 + 325 =
  7. 7.1 + 1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 =
  8. 8.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?
  9. 9.Leapfrog list (each number is the sum of the two before it): 6, 2, 8, 10, 18, 28, 46, 74, 120, 194. What is 11 × the 7th number?
  10. 10.Leapfrog list (each number is the sum of the two before it): 1, 1, 2, 3, 5, 8, 13, 21, 34, 55. What is 11 × the 7th number?
  11. 11.7 + 7 + 14 + 21 + 35 + 56 + 91 + 147 + 238 + 385 =
  12. 12.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?
  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. 14.2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 =
  15. 15.5 + 2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 =
  16. 16.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?
  17. 17.1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 =
  18. 18.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?
  19. 19.2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 =
  20. 20.A leapfrog list starts 1, 5 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, 3, 11, 14, 25, 39, 64, 103, 167, 270. What is 11 × the 7th number?
  22. 22.9 + 1 + 10 + 11 + 21 + 32 + 53 + 85 + 138 + 223 =
  23. 23.Leapfrog list (each number is the sum of the two before it): 1, 2, 3, 5, 8, 13, 21, 34, 55, 89. What is 11 × the 7th number?
  24. 24.Leapfrog list (each number is the sum of the two before it): 7, 1, 8, 9, 17, 26, 43, 69, 112, 181. What is 11 × the 7th number?
  25. 25.Leapfrog list (each number is the sum of the two before it): 5, 2, 7, 9, 16, 25, 41, 66, 107, 173. What is 11 × the 7th number?
  26. 26.8 + 8 + 16 + 24 + 40 + 64 + 104 + 168 + 272 + 440 =
  27. 27.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?
  28. 28.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?
  29. 29.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?
  30. 30.4 + 9 + 13 + 22 + 35 + 57 + 92 + 149 + 241 + 390 =
  31. 31.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?
  32. 32.A leapfrog list starts 7, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  33. 33.4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 + 356 =
  34. 34.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?
  35. 35.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?
  36. 36.9 + 2 + 11 + 13 + 24 + 37 + 61 + 98 + 159 + 257 =
  37. 37.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?
  38. 38.Leapfrog list (each number is the sum of the two before it): 8, 4, 12, 16, 28, 44, 72, 116, 188, 304. What is 11 × the 7th number?
  39. 39.Leapfrog list (each number is the sum of the two before it): 8, 1, 9, 10, 19, 29, 48, 77, 125, 202. What is 11 × the 7th number?
  40. 40.6 + 4 + 10 + 14 + 24 + 38 + 62 + 100 + 162 + 262 =

Answer key

  1. 1232
  2. 429
  3. 462
  4. 671
  5. 429
  6. 847
  7. 143
  8. 198
  9. 506
  10. 143
  11. 1001
  12. 616
  13. 407
  14. 726
  15. 451
  16. 1144
  17. 407
  18. 792
  19. 374
  20. 495
  21. 704
  22. 583
  23. 231
  24. 473
  25. 451
  26. 1144
  27. 847
  28. 583
  29. 968
  30. 1012
  31. 418
  32. 649
  33. 924
  34. 891
  35. 1177
  36. 671
  37. 1111
  38. 792
  39. 528
  40. 682

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