← The leapfrog sum trick lesson New set →

Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 505 · 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 4, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  2. 2.1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 =
  3. 3.2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 =
  4. 4.A leapfrog list starts 6, 3 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, 6, 8, 14, 22, 36, 58, 94, 152, 246. What is 11 × the 7th number?
  6. 6.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?
  7. 7.5 + 2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 =
  8. 8.9 + 1 + 10 + 11 + 21 + 32 + 53 + 85 + 138 + 223 =
  9. 9.4 + 4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 =
  10. 10.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?
  11. 11.3 + 8 + 11 + 19 + 30 + 49 + 79 + 128 + 207 + 335 =
  12. 12.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?
  13. 13.8 + 2 + 10 + 12 + 22 + 34 + 56 + 90 + 146 + 236 =
  14. 14.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?
  15. 15.A leapfrog list starts 6, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  16. 16.9 + 9 + 18 + 27 + 45 + 72 + 117 + 189 + 306 + 495 =
  17. 17.Leapfrog list (each number is the sum of the two before it): 7, 5, 12, 17, 29, 46, 75, 121, 196, 317. What is 11 × the 7th number?
  18. 18.3 + 7 + 10 + 17 + 27 + 44 + 71 + 115 + 186 + 301 =
  19. 19.A leapfrog list starts 7, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  20. 20.Leapfrog list (each number is the sum of the two before it): 1, 6, 7, 13, 20, 33, 53, 86, 139, 225. What is 11 × the 7th number?
  21. 21.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?
  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): 9, 5, 14, 19, 33, 52, 85, 137, 222, 359. What is 11 × the 7th number?
  24. 24.3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 + 369 =
  25. 25.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?
  26. 26.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?
  27. 27.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?
  28. 28.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?
  29. 29.A leapfrog list starts 2, 3 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): 1, 4, 5, 9, 14, 23, 37, 60, 97, 157. What is 11 × the 7th number?
  31. 31.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?
  32. 32.9 + 4 + 13 + 17 + 30 + 47 + 77 + 124 + 201 + 325 =
  33. 33.A leapfrog list starts 3, 8 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 4, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  35. 35.4 + 3 + 7 + 10 + 17 + 27 + 44 + 71 + 115 + 186 =
  36. 36.1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 + 327 =
  37. 37.A leapfrog list starts 1, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  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.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?
  40. 40.Leapfrog list (each number is the sum of the two before it): 8, 6, 14, 20, 34, 54, 88, 142, 230, 372. What is 11 × the 7th number?

Answer key

  1. 1012
  2. 319
  3. 374
  4. 594
  5. 638
  6. 319
  7. 451
  8. 583
  9. 572
  10. 836
  11. 869
  12. 616
  13. 616
  14. 671
  15. 418
  16. 1287
  17. 825
  18. 781
  19. 825
  20. 583
  21. 473
  22. 649
  23. 935
  24. 957
  25. 649
  26. 583
  27. 253
  28. 286
  29. 374
  30. 407
  31. 198
  32. 847
  33. 869
  34. 484
  35. 484
  36. 847
  37. 495
  38. 737
  39. 561
  40. 968

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