← The leapfrog sum trick lesson New set →

Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 811 · 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): 7, 2, 9, 11, 20, 31, 51, 82, 133, 215. What is 11 × the 7th number?
  2. 2.4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 + 356 =
  3. 3.Leapfrog list (each number is the sum of the two before it): 5, 5, 10, 15, 25, 40, 65, 105, 170, 275. What is 11 × the 7th number?
  4. 4.5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 + 343 =
  5. 5.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?
  6. 6.Leapfrog list (each number is the sum of the two before it): 3, 6, 9, 15, 24, 39, 63, 102, 165, 267. What is 11 × the 7th number?
  7. 7.A leapfrog list starts 8, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  8. 8.2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 + 348 =
  9. 9.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?
  10. 10.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?
  11. 11.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?
  12. 12.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?
  13. 13.3 + 8 + 11 + 19 + 30 + 49 + 79 + 128 + 207 + 335 =
  14. 14.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?
  15. 15.A leapfrog list starts 1, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  16. 16.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?
  17. 17.A leapfrog list starts 3, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  18. 18.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?
  19. 19.6 + 2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 =
  20. 20.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?
  21. 21.7 + 1 + 8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 =
  22. 22.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?
  23. 23.Leapfrog list (each number is the sum of the two before it): 6, 4, 10, 14, 24, 38, 62, 100, 162, 262. What is 11 × the 7th number?
  24. 24.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?
  25. 25.8 + 3 + 11 + 14 + 25 + 39 + 64 + 103 + 167 + 270 =
  26. 26.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?
  27. 27.6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 + 398 =
  28. 28.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?
  29. 29.6 + 1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 =
  30. 30.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?
  31. 31.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?
  32. 32.3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 + 233 =
  33. 33.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?
  34. 34.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?
  35. 35.1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 =
  36. 36.A leapfrog list starts 9, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  37. 37.A leapfrog list starts 5, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  38. 38.2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 + 314 =
  39. 39.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?
  40. 40.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?

Answer key

  1. 561
  2. 924
  3. 715
  4. 891
  5. 583
  6. 693
  7. 1144
  8. 902
  9. 308
  10. 704
  11. 847
  12. 924
  13. 869
  14. 253
  15. 671
  16. 968
  17. 781
  18. 253
  19. 506
  20. 462
  21. 473
  22. 528
  23. 682
  24. 638
  25. 704
  26. 517
  27. 1034
  28. 286
  29. 418
  30. 1232
  31. 407
  32. 605
  33. 847
  34. 473
  35. 495
  36. 1199
  37. 539
  38. 814
  39. 704
  40. 616

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