← The leapfrog sum trick lesson New set →

Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 160 · 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, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  2. 2.3 + 1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 =
  3. 3.Leapfrog list (each number is the sum of the two before it): 4, 4, 8, 12, 20, 32, 52, 84, 136, 220. What is 11 × the 7th number?
  4. 4.1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 =
  5. 5.8 + 1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 =
  6. 6.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?
  7. 7.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?
  8. 8.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?
  9. 9.4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 + 178 + 288 =
  10. 10.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?
  11. 11.Leapfrog list (each number is the sum of the two before it): 9, 3, 12, 15, 27, 42, 69, 111, 180, 291. What is 11 × the 7th number?
  12. 12.Leapfrog list (each number is the sum of the two before it): 6, 7, 13, 20, 33, 53, 86, 139, 225, 364. What is 11 × the 7th number?
  13. 13.7 + 7 + 14 + 21 + 35 + 56 + 91 + 147 + 238 + 385 =
  14. 14.8 + 7 + 15 + 22 + 37 + 59 + 96 + 155 + 251 + 406 =
  15. 15.2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 + 348 =
  16. 16.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?
  17. 17.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?
  18. 18.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?
  19. 19.A leapfrog list starts 9, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  20. 20.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?
  21. 21.A leapfrog list starts 4, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  22. 22.9 + 7 + 16 + 23 + 39 + 62 + 101 + 163 + 264 + 427 =
  23. 23.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?
  24. 24.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?
  25. 25.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?
  26. 26.A leapfrog list starts 3, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  27. 27.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?
  28. 28.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?
  29. 29.7 + 4 + 11 + 15 + 26 + 41 + 67 + 108 + 175 + 283 =
  30. 30.1 + 1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 =
  31. 31.A leapfrog list starts 8, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  32. 32.A leapfrog list starts 1, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  33. 33.A leapfrog list starts 7, 2 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 8, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  35. 35.6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 + 267 + 432 =
  36. 36.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?
  37. 37.1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 =
  38. 38.5 + 2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 =
  39. 39.2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 =
  40. 40.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?

Answer key

  1. 902
  2. 253
  3. 572
  4. 495
  5. 528
  6. 374
  7. 583
  8. 847
  9. 748
  10. 462
  11. 759
  12. 946
  13. 1001
  14. 1056
  15. 902
  16. 924
  17. 704
  18. 671
  19. 935
  20. 616
  21. 660
  22. 1111
  23. 968
  24. 528
  25. 286
  26. 605
  27. 1111
  28. 517
  29. 737
  30. 143
  31. 880
  32. 143
  33. 561
  34. 1144
  35. 1122
  36. 1001
  37. 231
  38. 451
  39. 374
  40. 627

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