← The leapfrog sum trick lesson New set →

Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 391 · 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. 1.3 + 8 + 11 + 19 + 30 + 49 + 79 + 128 + 207 + 335 =
  2. 2.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?
  3. 3.7 + 5 + 12 + 17 + 29 + 46 + 75 + 121 + 196 + 317 =
  4. 4.6 + 1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 =
  5. 5.6 + 2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 =
  6. 6.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?
  7. 7.A leapfrog list starts 7, 5 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): 5, 7, 12, 19, 31, 50, 81, 131, 212, 343. What is 11 × the 7th number?
  9. 9.8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 + 474 =
  10. 10.1 + 8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 =
  11. 11.5 + 2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 =
  12. 12.7 + 1 + 8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 =
  13. 13.Leapfrog list (each number is the sum of the two before it): 1, 2, 3, 5, 8, 13, 21, 34, 55, 89. What is 11 × the 7th number?
  14. 14.8 + 2 + 10 + 12 + 22 + 34 + 56 + 90 + 146 + 236 =
  15. 15.7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 + 453 =
  16. 16.8 + 1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 =
  17. 17.Leapfrog list (each number is the sum of the two before it): 6, 6, 12, 18, 30, 48, 78, 126, 204, 330. What is 11 × the 7th number?
  18. 18.Leapfrog list (each number is the sum of the two before it): 9, 1, 10, 11, 21, 32, 53, 85, 138, 223. What is 11 × the 7th number?
  19. 19.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?
  20. 20.Leapfrog list (each number is the sum of the two before it): 4, 3, 7, 10, 17, 27, 44, 71, 115, 186. What is 11 × the 7th number?
  21. 21.6 + 4 + 10 + 14 + 24 + 38 + 62 + 100 + 162 + 262 =
  22. 22.1 + 1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 =
  23. 23.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?
  24. 24.3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 + 267 =
  25. 25.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?
  26. 26.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?
  27. 27.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?
  28. 28.Leapfrog list (each number is the sum of the two before it): 1, 7, 8, 15, 23, 38, 61, 99, 160, 259. What is 11 × the 7th number?
  29. 29.9 + 6 + 15 + 21 + 36 + 57 + 93 + 150 + 243 + 393 =
  30. 30.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?
  31. 31.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?
  32. 32.A leapfrog list starts 1, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  33. 33.6 + 3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 =
  34. 34.3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 + 199 =
  35. 35.A leapfrog list starts 3, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  36. 36.A leapfrog list starts 7, 6 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 6, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  38. 38.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?
  39. 39.7 + 6 + 13 + 19 + 32 + 51 + 83 + 134 + 217 + 351 =
  40. 40.Leapfrog list (each number is the sum of the two before it): 4, 5, 9, 14, 23, 37, 60, 97, 157, 254. What is 11 × the 7th number?

Answer key

  1. 869
  2. 616
  3. 825
  4. 418
  5. 506
  6. 594
  7. 825
  8. 891
  9. 1232
  10. 759
  11. 451
  12. 473
  13. 231
  14. 616
  15. 1177
  16. 528
  17. 858
  18. 583
  19. 429
  20. 484
  21. 682
  22. 143
  23. 583
  24. 693
  25. 418
  26. 506
  27. 341
  28. 671
  29. 1023
  30. 605
  31. 902
  32. 319
  33. 594
  34. 517
  35. 429
  36. 913
  37. 858
  38. 143
  39. 913
  40. 660

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