← The leapfrog sum trick lesson New set →

Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 798 · 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 1, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  2. 2.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?
  3. 3.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?
  4. 4.Leapfrog list (each number is the sum of the two before it): 2, 5, 7, 12, 19, 31, 50, 81, 131, 212. What is 11 × the 7th number?
  5. 5.1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 + 259 =
  6. 6.4 + 3 + 7 + 10 + 17 + 27 + 44 + 71 + 115 + 186 =
  7. 7.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?
  8. 8.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?
  9. 9.Leapfrog list (each number is the sum of the two before it): 7, 6, 13, 19, 32, 51, 83, 134, 217, 351. What is 11 × the 7th number?
  10. 10.2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 =
  11. 11.Leapfrog list (each number is the sum of the two before it): 3, 8, 11, 19, 30, 49, 79, 128, 207, 335. What is 11 × the 7th number?
  12. 12.6 + 3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 =
  13. 13.Leapfrog list (each number is the sum of the two before it): 1, 3, 4, 7, 11, 18, 29, 47, 76, 123. What is 11 × the 7th number?
  14. 14.4 + 2 + 6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 =
  15. 15.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?
  16. 16.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?
  17. 17.9 + 9 + 18 + 27 + 45 + 72 + 117 + 189 + 306 + 495 =
  18. 18.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?
  19. 19.A leapfrog list starts 5, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  20. 20.Leapfrog list (each number is the sum of the two before it): 4, 7, 11, 18, 29, 47, 76, 123, 199, 322. What is 11 × the 7th number?
  21. 21.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?
  22. 22.3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 + 267 =
  23. 23.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?
  24. 24.7 + 2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 =
  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.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?
  27. 27.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?
  28. 28.2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 =
  29. 29.3 + 7 + 10 + 17 + 27 + 44 + 71 + 115 + 186 + 301 =
  30. 30.6 + 5 + 11 + 16 + 27 + 43 + 70 + 113 + 183 + 296 =
  31. 31.Leapfrog list (each number is the sum of the two before it): 9, 6, 15, 21, 36, 57, 93, 150, 243, 393. What is 11 × the 7th number?
  32. 32.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?
  33. 33.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?
  34. 34.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?
  35. 35.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?
  36. 36.5 + 2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 =
  37. 37.2 + 1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 =
  38. 38.9 + 5 + 14 + 19 + 33 + 52 + 85 + 137 + 222 + 359 =
  39. 39.A leapfrog list starts 7, 7 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 2, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?

Answer key

  1. 847
  2. 253
  3. 671
  4. 550
  5. 671
  6. 484
  7. 319
  8. 704
  9. 913
  10. 550
  11. 869
  12. 594
  13. 319
  14. 396
  15. 583
  16. 1012
  17. 1287
  18. 451
  19. 715
  20. 836
  21. 231
  22. 693
  23. 473
  24. 561
  25. 506
  26. 957
  27. 539
  28. 374
  29. 781
  30. 770
  31. 1023
  32. 374
  33. 902
  34. 1056
  35. 968
  36. 451
  37. 198
  38. 935
  39. 1001
  40. 550

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