← The leapfrog sum trick lesson New set →

Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 400 · 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 + 2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 =
  2. 2.9 + 4 + 13 + 17 + 30 + 47 + 77 + 124 + 201 + 325 =
  3. 3.A leapfrog list starts 1, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  4. 4.1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 =
  5. 5.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?
  6. 6.A leapfrog list starts 4, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  7. 7.5 + 3 + 8 + 11 + 19 + 30 + 49 + 79 + 128 + 207 =
  8. 8.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?
  9. 9.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?
  10. 10.2 + 1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 =
  11. 11.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?
  12. 12.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?
  13. 13.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?
  14. 14.3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 + 267 =
  15. 15.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?
  16. 16.4 + 2 + 6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 =
  17. 17.Leapfrog list (each number is the sum of the two before it): 4, 1, 5, 6, 11, 17, 28, 45, 73, 118. What is 11 × the 7th number?
  18. 18.Leapfrog list (each number is the sum of the two before it): 5, 6, 11, 17, 28, 45, 73, 118, 191, 309. What is 11 × the 7th number?
  19. 19.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?
  20. 20.A leapfrog list starts 9, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  21. 21.6 + 3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 =
  22. 22.A leapfrog list starts 9, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  23. 23.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?
  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.A leapfrog list starts 1, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  26. 26.5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 + 254 + 411 =
  27. 27.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?
  28. 28.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?
  29. 29.A leapfrog list starts 2, 8 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): 3, 1, 4, 5, 9, 14, 23, 37, 60, 97. What is 11 × the 7th number?
  31. 31.2 + 2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 =
  32. 32.Leapfrog list (each number is the sum of the two before it): 3, 5, 8, 13, 21, 34, 55, 89, 144, 233. What is 11 × the 7th number?
  33. 33.2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 =
  34. 34.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?
  35. 35.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?
  36. 36.2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 + 314 =
  37. 37.6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 + 267 + 432 =
  38. 38.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?
  39. 39.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?
  40. 40.A leapfrog list starts 6, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?

Answer key

  1. 561
  2. 847
  3. 583
  4. 495
  5. 616
  6. 748
  7. 539
  8. 913
  9. 858
  10. 198
  11. 968
  12. 473
  13. 583
  14. 693
  15. 880
  16. 396
  17. 308
  18. 803
  19. 726
  20. 1023
  21. 594
  22. 759
  23. 847
  24. 902
  25. 671
  26. 1067
  27. 836
  28. 803
  29. 814
  30. 253
  31. 286
  32. 605
  33. 550
  34. 583
  35. 792
  36. 814
  37. 1122
  38. 594
  39. 198
  40. 1034

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