← The leapfrog sum trick lesson New set →

Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 758 · 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 7, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  2. 2.9 + 5 + 14 + 19 + 33 + 52 + 85 + 137 + 222 + 359 =
  3. 3.7 + 7 + 14 + 21 + 35 + 56 + 91 + 147 + 238 + 385 =
  4. 4.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?
  5. 5.A leapfrog list starts 6, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  6. 6.Leapfrog list (each number is the sum of the two before it): 3, 8, 11, 19, 30, 49, 79, 128, 207, 335. What is 11 × the 7th number?
  7. 7.A leapfrog list starts 2, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  8. 8.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?
  9. 9.Leapfrog list (each number is the sum of the two before it): 8, 4, 12, 16, 28, 44, 72, 116, 188, 304. What is 11 × the 7th number?
  10. 10.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?
  11. 11.4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 + 356 =
  12. 12.Leapfrog list (each number is the sum of the two before it): 5, 2, 7, 9, 16, 25, 41, 66, 107, 173. What is 11 × the 7th number?
  13. 13.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?
  14. 14.5 + 1 + 6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 =
  15. 15.A leapfrog list starts 8, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  16. 16.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?
  17. 17.Leapfrog list (each number is the sum of the two before it): 9, 8, 17, 25, 42, 67, 109, 176, 285, 461. What is 11 × the 7th number?
  18. 18.Leapfrog list (each number is the sum of the two before it): 2, 3, 5, 8, 13, 21, 34, 55, 89, 144. What is 11 × the 7th number?
  19. 19.A leapfrog list starts 5, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  20. 20.7 + 3 + 10 + 13 + 23 + 36 + 59 + 95 + 154 + 249 =
  21. 21.7 + 6 + 13 + 19 + 32 + 51 + 83 + 134 + 217 + 351 =
  22. 22.Leapfrog list (each number is the sum of the two before it): 7, 9, 16, 25, 41, 66, 107, 173, 280, 453. What is 11 × the 7th number?
  23. 23.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?
  24. 24.A leapfrog list starts 1, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  25. 25.7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 + 259 + 419 =
  26. 26.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?
  27. 27.1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 =
  28. 28.A leapfrog list starts 9, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  29. 29.6 + 1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 =
  30. 30.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?
  31. 31.9 + 4 + 13 + 17 + 30 + 47 + 77 + 124 + 201 + 325 =
  32. 32.2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 + 314 =
  33. 33.8 + 3 + 11 + 14 + 25 + 39 + 64 + 103 + 167 + 270 =
  34. 34.6 + 2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 =
  35. 35.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?
  36. 36.2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 + 178 =
  37. 37.Leapfrog list (each number is the sum of the two before it): 1, 1, 2, 3, 5, 8, 13, 21, 34, 55. What is 11 × the 7th number?
  38. 38.5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 + 343 =
  39. 39.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?
  40. 40.Leapfrog list (each number is the sum of the two before it): 4, 9, 13, 22, 35, 57, 92, 149, 241, 390. What is 11 × the 7th number?

Answer key

  1. 913
  2. 935
  3. 1001
  4. 550
  5. 770
  6. 869
  7. 286
  8. 418
  9. 792
  10. 495
  11. 924
  12. 451
  13. 286
  14. 363
  15. 616
  16. 407
  17. 1199
  18. 374
  19. 539
  20. 649
  21. 913
  22. 1177
  23. 605
  24. 231
  25. 1089
  26. 968
  27. 319
  28. 583
  29. 418
  30. 1199
  31. 847
  32. 814
  33. 704
  34. 506
  35. 825
  36. 462
  37. 143
  38. 891
  39. 781
  40. 1012

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