← The leapfrog sum trick lesson New set →

Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 785 · 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): 6, 3, 9, 12, 21, 33, 54, 87, 141, 228. What is 11 × the 7th number?
  2. 2.Leapfrog list (each number is the sum of the two before it): 8, 1, 9, 10, 19, 29, 48, 77, 125, 202. What is 11 × the 7th number?
  3. 3.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?
  4. 4.A leapfrog list starts 4, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  5. 5.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?
  6. 6.Leapfrog list (each number is the sum of the two before it): 8, 4, 12, 16, 28, 44, 72, 116, 188, 304. What is 11 × the 7th number?
  7. 7.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?
  8. 8.A leapfrog list starts 1, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  9. 9.8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 + 474 =
  10. 10.8 + 2 + 10 + 12 + 22 + 34 + 56 + 90 + 146 + 236 =
  11. 11.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?
  12. 12.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?
  13. 13.Leapfrog list (each number is the sum of the two before it): 6, 5, 11, 16, 27, 43, 70, 113, 183, 296. What is 11 × the 7th number?
  14. 14.Leapfrog list (each number is the sum of the two before it): 1, 5, 6, 11, 17, 28, 45, 73, 118, 191. What is 11 × the 7th number?
  15. 15.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?
  16. 16.4 + 1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 =
  17. 17.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?
  18. 18.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?
  19. 19.Leapfrog list (each number is the sum of the two before it): 5, 6, 11, 17, 28, 45, 73, 118, 191, 309. What is 11 × the 7th number?
  20. 20.Leapfrog list (each number is the sum of the two before it): 1, 8, 9, 17, 26, 43, 69, 112, 181, 293. What is 11 × the 7th number?
  21. 21.3 + 2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 =
  22. 22.5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 + 233 + 377 =
  23. 23.Leapfrog list (each number is the sum of the two before it): 8, 8, 16, 24, 40, 64, 104, 168, 272, 440. What is 11 × the 7th number?
  24. 24.4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 + 178 + 288 =
  25. 25.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?
  26. 26.7 + 6 + 13 + 19 + 32 + 51 + 83 + 134 + 217 + 351 =
  27. 27.9 + 2 + 11 + 13 + 24 + 37 + 61 + 98 + 159 + 257 =
  28. 28.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?
  29. 29.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?
  30. 30.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?
  31. 31.Leapfrog list (each number is the sum of the two before it): 7, 2, 9, 11, 20, 31, 51, 82, 133, 215. What is 11 × the 7th number?
  32. 32.A leapfrog list starts 7, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  33. 33.9 + 4 + 13 + 17 + 30 + 47 + 77 + 124 + 201 + 325 =
  34. 34.7 + 3 + 10 + 13 + 23 + 36 + 59 + 95 + 154 + 249 =
  35. 35.4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 + 199 + 322 =
  36. 36.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?
  37. 37.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?
  38. 38.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?
  39. 39.3 + 8 + 11 + 19 + 30 + 49 + 79 + 128 + 207 + 335 =
  40. 40.Leapfrog list (each number is the sum of the two before it): 5, 9, 14, 23, 37, 60, 97, 157, 254, 411. What is 11 × the 7th number?

Answer key

  1. 594
  2. 528
  3. 1111
  4. 836
  5. 198
  6. 792
  7. 836
  8. 407
  9. 1232
  10. 616
  11. 913
  12. 924
  13. 770
  14. 495
  15. 759
  16. 308
  17. 143
  18. 572
  19. 803
  20. 759
  21. 341
  22. 979
  23. 1144
  24. 748
  25. 374
  26. 913
  27. 671
  28. 253
  29. 671
  30. 935
  31. 561
  32. 1177
  33. 847
  34. 649
  35. 836
  36. 869
  37. 891
  38. 462
  39. 869
  40. 1067

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