← The leapfrog sum trick lesson New set →

Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 643 · 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. 1.7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 + 259 + 419 =
  2. 2.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?
  3. 3.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?
  4. 4.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?
  5. 5.A leapfrog list starts 3, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  6. 6.9 + 4 + 13 + 17 + 30 + 47 + 77 + 124 + 201 + 325 =
  7. 7.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?
  8. 8.6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 + 267 + 432 =
  9. 9.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?
  10. 10.Leapfrog list (each number is the sum of the two before it): 2, 5, 7, 12, 19, 31, 50, 81, 131, 212. What is 11 × the 7th number?
  11. 11.A leapfrog list starts 2, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  12. 12.1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 =
  13. 13.3 + 2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 =
  14. 14.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?
  15. 15.A leapfrog list starts 5, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  16. 16.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?
  17. 17.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?
  18. 18.Leapfrog list (each number is the sum of the two before it): 9, 9, 18, 27, 45, 72, 117, 189, 306, 495. What is 11 × the 7th number?
  19. 19.9 + 2 + 11 + 13 + 24 + 37 + 61 + 98 + 159 + 257 =
  20. 20.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?
  21. 21.5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 + 309 =
  22. 22.3 + 3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 =
  23. 23.4 + 9 + 13 + 22 + 35 + 57 + 92 + 149 + 241 + 390 =
  24. 24.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?
  25. 25.1 + 8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 =
  26. 26.Leapfrog list (each number is the sum of the two before it): 1, 9, 10, 19, 29, 48, 77, 125, 202, 327. What is 11 × the 7th number?
  27. 27.A leapfrog list starts 8, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  28. 28.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?
  29. 29.2 + 2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 =
  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. 31.7 + 2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 =
  32. 32.8 + 1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 =
  33. 33.4 + 1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 =
  34. 34.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?
  35. 35.5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 + 343 =
  36. 36.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?
  37. 37.A leapfrog list starts 3, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  38. 38.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?
  39. 39.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?
  40. 40.4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 + 199 + 322 =

Answer key

  1. 1089
  2. 319
  3. 319
  4. 1144
  5. 517
  6. 847
  7. 1056
  8. 1122
  9. 528
  10. 550
  11. 198
  12. 495
  13. 341
  14. 638
  15. 803
  16. 374
  17. 649
  18. 1287
  19. 671
  20. 1089
  21. 803
  22. 429
  23. 1012
  24. 792
  25. 759
  26. 847
  27. 880
  28. 858
  29. 286
  30. 935
  31. 561
  32. 528
  33. 308
  34. 1023
  35. 891
  36. 924
  37. 781
  38. 913
  39. 484
  40. 836

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