← The leapfrog sum trick lesson New set →

Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 90 · 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 3, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  2. 2.6 + 4 + 10 + 14 + 24 + 38 + 62 + 100 + 162 + 262 =
  3. 3.5 + 2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 =
  4. 4.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?
  5. 5.Leapfrog list (each number is the sum of the two before it): 5, 3, 8, 11, 19, 30, 49, 79, 128, 207. What is 11 × the 7th number?
  6. 6.Leapfrog list (each number is the sum of the two before it): 6, 8, 14, 22, 36, 58, 94, 152, 246, 398. What is 11 × the 7th number?
  7. 7.1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 =
  8. 8.2 + 2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 =
  9. 9.Leapfrog list (each number is the sum of the two before it): 1, 5, 6, 11, 17, 28, 45, 73, 118, 191. What is 11 × the 7th number?
  10. 10.A leapfrog list starts 5, 4 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): 3, 6, 9, 15, 24, 39, 63, 102, 165, 267. What is 11 × the 7th number?
  12. 12.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?
  13. 13.2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 + 348 =
  14. 14.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?
  15. 15.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?
  16. 16.5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 + 254 + 411 =
  17. 17.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?
  18. 18.3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 + 369 =
  19. 19.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?
  20. 20.8 + 1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 =
  21. 21.2 + 1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 =
  22. 22.6 + 6 + 12 + 18 + 30 + 48 + 78 + 126 + 204 + 330 =
  23. 23.6 + 3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 =
  24. 24.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?
  25. 25.Leapfrog list (each number is the sum of the two before it): 4, 2, 6, 8, 14, 22, 36, 58, 94, 152. What is 11 × the 7th number?
  26. 26.6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 + 398 =
  27. 27.6 + 2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 =
  28. 28.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?
  29. 29.2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 =
  30. 30.2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 + 314 =
  31. 31.7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 + 259 + 419 =
  32. 32.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?
  33. 33.A leapfrog list starts 1, 9 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 2, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  36. 36.3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 + 199 =
  37. 37.2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 + 178 =
  38. 38.1 + 8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 =
  39. 39.A leapfrog list starts 4, 2 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 4, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?

Answer key

  1. 605
  2. 682
  3. 451
  4. 781
  5. 539
  6. 1034
  7. 319
  8. 286
  9. 495
  10. 627
  11. 693
  12. 583
  13. 902
  14. 517
  15. 594
  16. 1067
  17. 792
  18. 957
  19. 913
  20. 528
  21. 198
  22. 858
  23. 594
  24. 814
  25. 396
  26. 1034
  27. 506
  28. 253
  29. 550
  30. 814
  31. 1089
  32. 495
  33. 847
  34. 1232
  35. 462
  36. 517
  37. 462
  38. 759
  39. 396
  40. 308

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