← The leapfrog sum trick lesson New set →

Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 342 · 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 2, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  2. 2.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?
  3. 3.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?
  4. 4.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?
  5. 5.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?
  6. 6.Leapfrog list (each number is the sum of the two before it): 8, 7, 15, 22, 37, 59, 96, 155, 251, 406. What is 11 × the 7th number?
  7. 7.Leapfrog list (each number is the sum of the two before it): 7, 3, 10, 13, 23, 36, 59, 95, 154, 249. What is 11 × the 7th number?
  8. 8.1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 =
  9. 9.Leapfrog list (each number is the sum of the two before it): 2, 6, 8, 14, 22, 36, 58, 94, 152, 246. What is 11 × the 7th number?
  10. 10.9 + 5 + 14 + 19 + 33 + 52 + 85 + 137 + 222 + 359 =
  11. 11.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?
  12. 12.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?
  13. 13.8 + 4 + 12 + 16 + 28 + 44 + 72 + 116 + 188 + 304 =
  14. 14.Leapfrog list (each number is the sum of the two before it): 2, 8, 10, 18, 28, 46, 74, 120, 194, 314. What is 11 × the 7th number?
  15. 15.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?
  16. 16.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?
  17. 17.6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 + 398 =
  18. 18.A leapfrog list starts 8, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  19. 19.6 + 6 + 12 + 18 + 30 + 48 + 78 + 126 + 204 + 330 =
  20. 20.Leapfrog list (each number is the sum of the two before it): 6, 5, 11, 16, 27, 43, 70, 113, 183, 296. What is 11 × the 7th number?
  21. 21.2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 =
  22. 22.4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 + 199 + 322 =
  23. 23.Leapfrog list (each number is the sum of the two before it): 3, 2, 5, 7, 12, 19, 31, 50, 81, 131. What is 11 × the 7th number?
  24. 24.4 + 4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 =
  25. 25.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?
  26. 26.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?
  27. 27.A leapfrog list starts 7, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  28. 28.3 + 1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 =
  29. 29.A leapfrog list starts 3, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  30. 30.4 + 1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 =
  31. 31.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?
  32. 32.8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 + 474 =
  33. 33.2 + 2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 =
  34. 34.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?
  35. 35.Leapfrog list (each number is the sum of the two before it): 4, 1, 5, 6, 11, 17, 28, 45, 73, 118. What is 11 × the 7th number?
  36. 36.4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 + 356 =
  37. 37.7 + 2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 =
  38. 38.5 + 2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 =
  39. 39.Leapfrog list (each number is the sum of the two before it): 4, 9, 13, 22, 35, 57, 92, 149, 241, 390. What is 11 × the 7th number?
  40. 40.5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 + 343 =

Answer key

  1. 462
  2. 715
  3. 957
  4. 407
  5. 1111
  6. 1056
  7. 649
  8. 407
  9. 638
  10. 935
  11. 473
  12. 836
  13. 792
  14. 814
  15. 462
  16. 704
  17. 1034
  18. 528
  19. 858
  20. 770
  21. 550
  22. 836
  23. 341
  24. 572
  25. 506
  26. 759
  27. 1089
  28. 253
  29. 517
  30. 308
  31. 1111
  32. 1232
  33. 286
  34. 847
  35. 308
  36. 924
  37. 561
  38. 451
  39. 1012
  40. 891

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