← The leapfrog sum trick lesson New set →

Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 966 · 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): 4, 3, 7, 10, 17, 27, 44, 71, 115, 186. What is 11 × the 7th number?
  2. 2.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?
  3. 3.2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 + 314 =
  4. 4.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?
  5. 5.3 + 1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 =
  6. 6.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?
  7. 7.7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 + 453 =
  8. 8.Leapfrog list (each number is the sum of the two before it): 8, 2, 10, 12, 22, 34, 56, 90, 146, 236. What is 11 × the 7th number?
  9. 9.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?
  10. 10.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?
  11. 11.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?
  12. 12.Leapfrog list (each number is the sum of the two before it): 5, 1, 6, 7, 13, 20, 33, 53, 86, 139. What is 11 × the 7th number?
  13. 13.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?
  14. 14.2 + 2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 =
  15. 15.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?
  16. 16.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?
  17. 17.Leapfrog list (each number is the sum of the two before it): 7, 7, 14, 21, 35, 56, 91, 147, 238, 385. What is 11 × the 7th number?
  18. 18.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?
  19. 19.A leapfrog list starts 2, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  20. 20.3 + 3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 =
  21. 21.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?
  22. 22.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?
  23. 23.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?
  24. 24.4 + 3 + 7 + 10 + 17 + 27 + 44 + 71 + 115 + 186 =
  25. 25.5 + 3 + 8 + 11 + 19 + 30 + 49 + 79 + 128 + 207 =
  26. 26.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?
  27. 27.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?
  28. 28.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?
  29. 29.3 + 2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 =
  30. 30.1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 + 327 =
  31. 31.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?
  32. 32.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?
  33. 33.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?
  34. 34.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?
  35. 35.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?
  36. 36.7 + 4 + 11 + 15 + 26 + 41 + 67 + 108 + 175 + 283 =
  37. 37.6 + 5 + 11 + 16 + 27 + 43 + 70 + 113 + 183 + 296 =
  38. 38.A leapfrog list starts 4, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  39. 39.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?
  40. 40.A leapfrog list starts 5, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?

Answer key

  1. 484
  2. 286
  3. 814
  4. 638
  5. 253
  6. 902
  7. 1177
  8. 616
  9. 946
  10. 759
  11. 407
  12. 363
  13. 715
  14. 286
  15. 1111
  16. 198
  17. 1001
  18. 891
  19. 638
  20. 429
  21. 847
  22. 649
  23. 1056
  24. 484
  25. 539
  26. 462
  27. 671
  28. 1001
  29. 341
  30. 847
  31. 660
  32. 605
  33. 308
  34. 616
  35. 319
  36. 737
  37. 770
  38. 924
  39. 880
  40. 627

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