← The leapfrog sum trick lesson New set →

Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 935 · 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): 1, 3, 4, 7, 11, 18, 29, 47, 76, 123. What is 11 × the 7th number?
  2. 2.1 + 6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 + 225 =
  3. 3.9 + 9 + 18 + 27 + 45 + 72 + 117 + 189 + 306 + 495 =
  4. 4.2 + 6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 =
  5. 5.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?
  6. 6.A leapfrog list starts 7, 8 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): 8, 1, 9, 10, 19, 29, 48, 77, 125, 202. What is 11 × the 7th number?
  8. 8.Leapfrog list (each number is the sum of the two before it): 6, 6, 12, 18, 30, 48, 78, 126, 204, 330. What is 11 × the 7th number?
  9. 9.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?
  10. 10.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?
  11. 11.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?
  12. 12.Leapfrog list (each number is the sum of the two before it): 1, 7, 8, 15, 23, 38, 61, 99, 160, 259. What is 11 × the 7th number?
  13. 13.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?
  14. 14.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?
  15. 15.9 + 5 + 14 + 19 + 33 + 52 + 85 + 137 + 222 + 359 =
  16. 16.2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 =
  17. 17.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?
  18. 18.A leapfrog list starts 8, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  19. 19.1 + 1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 =
  20. 20.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?
  21. 21.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?
  22. 22.Leapfrog list (each number is the sum of the two before it): 6, 4, 10, 14, 24, 38, 62, 100, 162, 262. What is 11 × the 7th number?
  23. 23.A leapfrog list starts 3, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  24. 24.7 + 4 + 11 + 15 + 26 + 41 + 67 + 108 + 175 + 283 =
  25. 25.8 + 5 + 13 + 18 + 31 + 49 + 80 + 129 + 209 + 338 =
  26. 26.2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 + 348 =
  27. 27.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?
  28. 28.3 + 7 + 10 + 17 + 27 + 44 + 71 + 115 + 186 + 301 =
  29. 29.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?
  30. 30.A leapfrog list starts 8, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  31. 31.2 + 2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 =
  32. 32.A leapfrog list starts 2, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  33. 33.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?
  34. 34.8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 + 474 =
  35. 35.A leapfrog list starts 9, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  36. 36.5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 + 233 + 377 =
  37. 37.Leapfrog list (each number is the sum of the two before it): 9, 4, 13, 17, 30, 47, 77, 124, 201, 325. What is 11 × the 7th number?
  38. 38.6 + 3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 =
  39. 39.2 + 1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 =
  40. 40.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?

Answer key

  1. 319
  2. 583
  3. 1287
  4. 638
  5. 462
  6. 1089
  7. 528
  8. 858
  9. 759
  10. 319
  11. 286
  12. 671
  13. 935
  14. 924
  15. 935
  16. 374
  17. 847
  18. 792
  19. 143
  20. 660
  21. 594
  22. 682
  23. 341
  24. 737
  25. 880
  26. 902
  27. 869
  28. 781
  29. 407
  30. 1056
  31. 286
  32. 726
  33. 1199
  34. 1232
  35. 671
  36. 979
  37. 847
  38. 594
  39. 198
  40. 198

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