← The leapfrog sum trick lesson New set →

Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 926 · 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, 1, 7, 8, 15, 23, 38, 61, 99, 160. What is 11 × the 7th number?
  2. 2.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?
  3. 3.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?
  4. 4.2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 =
  5. 5.Leapfrog list (each number is the sum of the two before it): 7, 1, 8, 9, 17, 26, 43, 69, 112, 181. What is 11 × the 7th number?
  6. 6.8 + 4 + 12 + 16 + 28 + 44 + 72 + 116 + 188 + 304 =
  7. 7.1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 =
  8. 8.Leapfrog list (each number is the sum of the two before it): 7, 9, 16, 25, 41, 66, 107, 173, 280, 453. What is 11 × the 7th number?
  9. 9.1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 =
  10. 10.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?
  11. 11.A leapfrog list starts 5, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  12. 12.3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 + 369 =
  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. 14.6 + 6 + 12 + 18 + 30 + 48 + 78 + 126 + 204 + 330 =
  15. 15.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?
  16. 16.5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 + 254 + 411 =
  17. 17.9 + 6 + 15 + 21 + 36 + 57 + 93 + 150 + 243 + 393 =
  18. 18.2 + 1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 =
  19. 19.2 + 6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 =
  20. 20.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?
  21. 21.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?
  22. 22.2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 =
  23. 23.7 + 7 + 14 + 21 + 35 + 56 + 91 + 147 + 238 + 385 =
  24. 24.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?
  25. 25.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?
  26. 26.4 + 4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 =
  27. 27.2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 =
  28. 28.A leapfrog list starts 3, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  29. 29.7 + 4 + 11 + 15 + 26 + 41 + 67 + 108 + 175 + 283 =
  30. 30.4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 + 178 + 288 =
  31. 31.A leapfrog list starts 7, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  32. 32.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?
  33. 33.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?
  34. 34.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?
  35. 35.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?
  36. 36.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?
  37. 37.3 + 2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 =
  38. 38.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?
  39. 39.Leapfrog list (each number is the sum of the two before it): 2, 7, 9, 16, 25, 41, 66, 107, 173, 280. What is 11 × the 7th number?
  40. 40.Leapfrog list (each number is the sum of the two before it): 5, 3, 8, 11, 19, 30, 49, 79, 128, 207. What is 11 × the 7th number?

Answer key

  1. 418
  2. 506
  3. 935
  4. 374
  5. 473
  6. 792
  7. 231
  8. 1177
  9. 407
  10. 374
  11. 1067
  12. 957
  13. 319
  14. 858
  15. 957
  16. 1067
  17. 1023
  18. 198
  19. 638
  20. 792
  21. 1144
  22. 726
  23. 1001
  24. 902
  25. 627
  26. 572
  27. 550
  28. 693
  29. 737
  30. 748
  31. 737
  32. 902
  33. 363
  34. 495
  35. 143
  36. 572
  37. 341
  38. 638
  39. 726
  40. 539

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