← The leapfrog sum trick lesson New set →

Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 297 · 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): 1, 8, 9, 17, 26, 43, 69, 112, 181, 293. What is 11 × the 7th number?
  2. 2.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?
  3. 3.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?
  4. 4.9 + 9 + 18 + 27 + 45 + 72 + 117 + 189 + 306 + 495 =
  5. 5.A leapfrog list starts 4, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  6. 6.5 + 3 + 8 + 11 + 19 + 30 + 49 + 79 + 128 + 207 =
  7. 7.A leapfrog list starts 2, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  8. 8.5 + 1 + 6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 =
  9. 9.A leapfrog list starts 6, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  10. 10.A leapfrog list starts 3, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  11. 11.2 + 2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 =
  12. 12.4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 + 356 =
  13. 13.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?
  14. 14.A leapfrog list starts 9, 7 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 8, 5 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 2, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  17. 17.8 + 4 + 12 + 16 + 28 + 44 + 72 + 116 + 188 + 304 =
  18. 18.1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 =
  19. 19.A leapfrog list starts 8, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  20. 20.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?
  21. 21.4 + 4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 =
  22. 22.A leapfrog list starts 2, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  23. 23.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?
  24. 24.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?
  25. 25.8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 + 474 =
  26. 26.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?
  27. 27.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?
  28. 28.9 + 7 + 16 + 23 + 39 + 62 + 101 + 163 + 264 + 427 =
  29. 29.9 + 1 + 10 + 11 + 21 + 32 + 53 + 85 + 138 + 223 =
  30. 30.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?
  31. 31.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?
  32. 32.2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 + 348 =
  33. 33.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?
  34. 34.Leapfrog list (each number is the sum of the two before it): 6, 3, 9, 12, 21, 33, 54, 87, 141, 228. What is 11 × the 7th number?
  35. 35.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?
  36. 36.1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 + 327 =
  37. 37.Leapfrog list (each number is the sum of the two before it): 9, 9, 18, 27, 45, 72, 117, 189, 306, 495. What is 11 × the 7th number?
  38. 38.Leapfrog list (each number is the sum of the two before it): 5, 4, 9, 13, 22, 35, 57, 92, 149, 241. What is 11 × the 7th number?
  39. 39.A leapfrog list starts 5, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  40. 40.A leapfrog list starts 1, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?

Answer key

  1. 759
  2. 759
  3. 605
  4. 1287
  5. 484
  6. 539
  7. 550
  8. 363
  9. 1122
  10. 341
  11. 286
  12. 924
  13. 506
  14. 1111
  15. 880
  16. 462
  17. 792
  18. 231
  19. 968
  20. 418
  21. 572
  22. 726
  23. 1034
  24. 957
  25. 1232
  26. 1144
  27. 583
  28. 1111
  29. 583
  30. 143
  31. 792
  32. 902
  33. 825
  34. 594
  35. 451
  36. 847
  37. 1287
  38. 627
  39. 1067
  40. 759

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