← The leapfrog sum trick lesson New set →

Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 217 · 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. 1.8 + 3 + 11 + 14 + 25 + 39 + 64 + 103 + 167 + 270 =
  2. 2.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?
  3. 3.A leapfrog list starts 9, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  4. 4.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?
  5. 5.Leapfrog list (each number is the sum of the two before it): 3, 7, 10, 17, 27, 44, 71, 115, 186, 301. What is 11 × the 7th number?
  6. 6.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?
  7. 7.4 + 2 + 6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 =
  8. 8.Leapfrog list (each number is the sum of the two before it): 5, 3, 8, 11, 19, 30, 49, 79, 128, 207. What is 11 × the 7th number?
  9. 9.9 + 5 + 14 + 19 + 33 + 52 + 85 + 137 + 222 + 359 =
  10. 10.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?
  11. 11.2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 =
  12. 12.Leapfrog list (each number is the sum of the two before it): 4, 4, 8, 12, 20, 32, 52, 84, 136, 220. What is 11 × the 7th number?
  13. 13.7 + 5 + 12 + 17 + 29 + 46 + 75 + 121 + 196 + 317 =
  14. 14.4 + 1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 =
  15. 15.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?
  16. 16.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?
  17. 17.6 + 6 + 12 + 18 + 30 + 48 + 78 + 126 + 204 + 330 =
  18. 18.Leapfrog list (each number is the sum of the two before it): 3, 9, 12, 21, 33, 54, 87, 141, 228, 369. What is 11 × the 7th number?
  19. 19.A leapfrog list starts 7, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  20. 20.7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 + 259 + 419 =
  21. 21.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?
  22. 22.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?
  23. 23.A leapfrog list starts 2, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  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.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?
  26. 26.9 + 1 + 10 + 11 + 21 + 32 + 53 + 85 + 138 + 223 =
  27. 27.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?
  28. 28.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?
  29. 29.1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 =
  30. 30.Leapfrog list (each number is the sum of the two before it): 1, 3, 4, 7, 11, 18, 29, 47, 76, 123. What is 11 × the 7th number?
  31. 31.5 + 1 + 6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 =
  32. 32.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?
  33. 33.3 + 1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 =
  34. 34.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?
  35. 35.5 + 2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 =
  36. 36.Leapfrog list (each number is the sum of the two before it): 9, 8, 17, 25, 42, 67, 109, 176, 285, 461. What is 11 × the 7th number?
  37. 37.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?
  38. 38.9 + 7 + 16 + 23 + 39 + 62 + 101 + 163 + 264 + 427 =
  39. 39.Leapfrog list (each number is the sum of the two before it): 4, 8, 12, 20, 32, 52, 84, 136, 220, 356. What is 11 × the 7th number?
  40. 40.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?

Answer key

  1. 704
  2. 143
  3. 847
  4. 847
  5. 781
  6. 253
  7. 396
  8. 539
  9. 935
  10. 1287
  11. 550
  12. 572
  13. 825
  14. 308
  15. 1023
  16. 253
  17. 858
  18. 957
  19. 1001
  20. 1089
  21. 528
  22. 1177
  23. 638
  24. 715
  25. 902
  26. 583
  27. 671
  28. 198
  29. 319
  30. 319
  31. 363
  32. 803
  33. 253
  34. 198
  35. 451
  36. 1199
  37. 517
  38. 1111
  39. 924
  40. 561

Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks