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Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 355 · 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 4, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  2. 2.A leapfrog list starts 6, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  3. 3.3 + 1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 =
  4. 4.5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 + 343 =
  5. 5.A leapfrog list starts 1, 2 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 9, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  7. 7.Leapfrog list (each number is the sum of the two before it): 1, 9, 10, 19, 29, 48, 77, 125, 202, 327. What is 11 × the 7th number?
  8. 8.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?
  9. 9.2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 + 348 =
  10. 10.2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 + 314 =
  11. 11.A leapfrog list starts 1, 3 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 8, 9 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): 8, 4, 12, 16, 28, 44, 72, 116, 188, 304. What is 11 × the 7th number?
  14. 14.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?
  15. 15.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?
  16. 16.6 + 4 + 10 + 14 + 24 + 38 + 62 + 100 + 162 + 262 =
  17. 17.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?
  18. 18.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?
  19. 19.6 + 1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 =
  20. 20.1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 =
  21. 21.9 + 2 + 11 + 13 + 24 + 37 + 61 + 98 + 159 + 257 =
  22. 22.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?
  23. 23.5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 + 309 =
  24. 24.7 + 2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 =
  25. 25.A leapfrog list starts 9, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  26. 26.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?
  27. 27.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?
  28. 28.Leapfrog list (each number is the sum of the two before it): 9, 5, 14, 19, 33, 52, 85, 137, 222, 359. What is 11 × the 7th number?
  29. 29.8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 + 474 =
  30. 30.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?
  31. 31.2 + 2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 =
  32. 32.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?
  33. 33.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?
  34. 34.2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 =
  35. 35.Leapfrog list (each number is the sum of the two before it): 2, 2, 4, 6, 10, 16, 26, 42, 68, 110. What is 11 × the 7th number?
  36. 36.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?
  37. 37.9 + 1 + 10 + 11 + 21 + 32 + 53 + 85 + 138 + 223 =
  38. 38.2 + 6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 =
  39. 39.1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 =
  40. 40.1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 + 259 =

Answer key

  1. 308
  2. 506
  3. 253
  4. 891
  5. 231
  6. 935
  7. 847
  8. 1232
  9. 902
  10. 814
  11. 319
  12. 1232
  13. 792
  14. 704
  15. 836
  16. 682
  17. 825
  18. 396
  19. 418
  20. 407
  21. 671
  22. 561
  23. 803
  24. 561
  25. 1023
  26. 902
  27. 143
  28. 935
  29. 1232
  30. 803
  31. 286
  32. 1111
  33. 473
  34. 726
  35. 286
  36. 825
  37. 583
  38. 638
  39. 231
  40. 671

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