← The leapfrog sum trick lesson New set →

Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 445 · 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): 5, 2, 7, 9, 16, 25, 41, 66, 107, 173. What is 11 × the 7th number?
  2. 2.7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 + 453 =
  3. 3.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?
  4. 4.4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 + 178 + 288 =
  5. 5.A leapfrog list starts 1, 6 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 7, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  7. 7.A leapfrog list starts 4, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  8. 8.Leapfrog list (each number is the sum of the two before it): 3, 3, 6, 9, 15, 24, 39, 63, 102, 165. What is 11 × the 7th number?
  9. 9.7 + 2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 =
  10. 10.4 + 3 + 7 + 10 + 17 + 27 + 44 + 71 + 115 + 186 =
  11. 11.5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 + 343 =
  12. 12.6 + 6 + 12 + 18 + 30 + 48 + 78 + 126 + 204 + 330 =
  13. 13.5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 + 254 + 411 =
  14. 14.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?
  15. 15.6 + 1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 =
  16. 16.A leapfrog list starts 6, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  17. 17.5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 + 309 =
  18. 18.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?
  19. 19.A leapfrog list starts 6, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  20. 20.6 + 2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 =
  21. 21.8 + 3 + 11 + 14 + 25 + 39 + 64 + 103 + 167 + 270 =
  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. 23.9 + 3 + 12 + 15 + 27 + 42 + 69 + 111 + 180 + 291 =
  24. 24.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?
  25. 25.1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 =
  26. 26.8 + 4 + 12 + 16 + 28 + 44 + 72 + 116 + 188 + 304 =
  27. 27.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?
  28. 28.7 + 4 + 11 + 15 + 26 + 41 + 67 + 108 + 175 + 283 =
  29. 29.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?
  30. 30.1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 =
  31. 31.4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 + 254 =
  32. 32.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?
  33. 33.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?
  34. 34.Leapfrog list (each number is the sum of the two before it): 2, 3, 5, 8, 13, 21, 34, 55, 89, 144. What is 11 × the 7th number?
  35. 35.2 + 1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 =
  36. 36.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?
  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 + 2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 =
  39. 39.Leapfrog list (each number is the sum of the two before it): 6, 1, 7, 8, 15, 23, 38, 61, 99, 160. What is 11 × the 7th number?
  40. 40.A leapfrog list starts 5, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?

Answer key

  1. 451
  2. 1177
  3. 198
  4. 748
  5. 583
  6. 1089
  7. 1012
  8. 429
  9. 561
  10. 484
  11. 891
  12. 858
  13. 1067
  14. 1177
  15. 418
  16. 946
  17. 803
  18. 1111
  19. 858
  20. 506
  21. 704
  22. 726
  23. 759
  24. 1287
  25. 407
  26. 792
  27. 935
  28. 737
  29. 198
  30. 319
  31. 660
  32. 539
  33. 924
  34. 374
  35. 198
  36. 627
  37. 539
  38. 286
  39. 418
  40. 891

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