← The leapfrog sum trick lesson New set →

Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 820 · 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 6, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  2. 2.Leapfrog list (each number is the sum of the two before it): 5, 8, 13, 21, 34, 55, 89, 144, 233, 377. What is 11 × the 7th number?
  3. 3.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?
  4. 4.5 + 1 + 6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 =
  5. 5.6 + 4 + 10 + 14 + 24 + 38 + 62 + 100 + 162 + 262 =
  6. 6.A leapfrog list starts 6, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  7. 7.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?
  8. 8.9 + 5 + 14 + 19 + 33 + 52 + 85 + 137 + 222 + 359 =
  9. 9.8 + 7 + 15 + 22 + 37 + 59 + 96 + 155 + 251 + 406 =
  10. 10.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?
  11. 11.1 + 8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 =
  12. 12.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?
  13. 13.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?
  14. 14.A leapfrog list starts 9, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  15. 15.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?
  16. 16.3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 + 233 =
  17. 17.2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 + 314 =
  18. 18.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?
  19. 19.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?
  20. 20.7 + 2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 =
  21. 21.Leapfrog list (each number is the sum of the two before it): 1, 1, 2, 3, 5, 8, 13, 21, 34, 55. What is 11 × the 7th number?
  22. 22.6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 + 398 =
  23. 23.9 + 1 + 10 + 11 + 21 + 32 + 53 + 85 + 138 + 223 =
  24. 24.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?
  25. 25.4 + 3 + 7 + 10 + 17 + 27 + 44 + 71 + 115 + 186 =
  26. 26.4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 + 356 =
  27. 27.7 + 7 + 14 + 21 + 35 + 56 + 91 + 147 + 238 + 385 =
  28. 28.Leapfrog list (each number is the sum of the two before it): 9, 2, 11, 13, 24, 37, 61, 98, 159, 257. What is 11 × the 7th number?
  29. 29.5 + 5 + 10 + 15 + 25 + 40 + 65 + 105 + 170 + 275 =
  30. 30.7 + 1 + 8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 =
  31. 31.A leapfrog list starts 7, 3 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): 8, 4, 12, 16, 28, 44, 72, 116, 188, 304. What is 11 × the 7th number?
  33. 33.Leapfrog list (each number is the sum of the two before it): 3, 1, 4, 5, 9, 14, 23, 37, 60, 97. What is 11 × the 7th number?
  34. 34.8 + 2 + 10 + 12 + 22 + 34 + 56 + 90 + 146 + 236 =
  35. 35.8 + 5 + 13 + 18 + 31 + 49 + 80 + 129 + 209 + 338 =
  36. 36.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?
  37. 37.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?
  38. 38.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?
  39. 39.2 + 2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 =
  40. 40.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?

Answer key

  1. 858
  2. 979
  3. 638
  4. 363
  5. 682
  6. 506
  7. 451
  8. 935
  9. 1056
  10. 1111
  11. 759
  12. 627
  13. 847
  14. 1199
  15. 462
  16. 605
  17. 814
  18. 1067
  19. 1023
  20. 561
  21. 143
  22. 1034
  23. 583
  24. 484
  25. 484
  26. 924
  27. 1001
  28. 671
  29. 715
  30. 473
  31. 649
  32. 792
  33. 253
  34. 616
  35. 880
  36. 1001
  37. 759
  38. 737
  39. 286
  40. 319

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