← The leapfrog sum trick lesson New set →

Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 323 · 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): 9, 5, 14, 19, 33, 52, 85, 137, 222, 359. What is 11 × the 7th number?
  2. 2.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?
  3. 3.1 + 6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 + 225 =
  4. 4.A leapfrog list starts 8, 3 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): 8, 1, 9, 10, 19, 29, 48, 77, 125, 202. What is 11 × the 7th number?
  6. 6.8 + 1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 =
  7. 7.A leapfrog list starts 8, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  8. 8.9 + 2 + 11 + 13 + 24 + 37 + 61 + 98 + 159 + 257 =
  9. 9.2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 + 314 =
  10. 10.Leapfrog list (each number is the sum of the two before it): 2, 8, 10, 18, 28, 46, 74, 120, 194, 314. What is 11 × the 7th number?
  11. 11.Leapfrog list (each number is the sum of the two before it): 6, 1, 7, 8, 15, 23, 38, 61, 99, 160. What is 11 × the 7th number?
  12. 12.Leapfrog list (each number is the sum of the two before it): 4, 4, 8, 12, 20, 32, 52, 84, 136, 220. What is 11 × the 7th number?
  13. 13.9 + 6 + 15 + 21 + 36 + 57 + 93 + 150 + 243 + 393 =
  14. 14.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?
  15. 15.4 + 3 + 7 + 10 + 17 + 27 + 44 + 71 + 115 + 186 =
  16. 16.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?
  17. 17.Leapfrog list (each number is the sum of the two before it): 5, 8, 13, 21, 34, 55, 89, 144, 233, 377. What is 11 × the 7th number?
  18. 18.A leapfrog list starts 7, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  19. 19.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?
  20. 20.1 + 1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 =
  21. 21.1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 =
  22. 22.3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 + 199 =
  23. 23.Leapfrog list (each number is the sum of the two before it): 7, 7, 14, 21, 35, 56, 91, 147, 238, 385. What is 11 × the 7th number?
  24. 24.2 + 1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 =
  25. 25.3 + 7 + 10 + 17 + 27 + 44 + 71 + 115 + 186 + 301 =
  26. 26.2 + 2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 =
  27. 27.9 + 1 + 10 + 11 + 21 + 32 + 53 + 85 + 138 + 223 =
  28. 28.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?
  29. 29.A leapfrog list starts 6, 2 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): 1, 4, 5, 9, 14, 23, 37, 60, 97, 157. What is 11 × the 7th number?
  31. 31.1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 =
  32. 32.5 + 2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 =
  33. 33.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?
  34. 34.8 + 7 + 15 + 22 + 37 + 59 + 96 + 155 + 251 + 406 =
  35. 35.A leapfrog list starts 7, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  36. 36.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?
  37. 37.7 + 3 + 10 + 13 + 23 + 36 + 59 + 95 + 154 + 249 =
  38. 38.7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 + 259 + 419 =
  39. 39.8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 + 474 =
  40. 40.5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 + 254 + 411 =

Answer key

  1. 935
  2. 913
  3. 583
  4. 704
  5. 528
  6. 528
  7. 1144
  8. 671
  9. 814
  10. 814
  11. 418
  12. 572
  13. 1023
  14. 1023
  15. 484
  16. 539
  17. 979
  18. 473
  19. 396
  20. 143
  21. 407
  22. 517
  23. 1001
  24. 198
  25. 781
  26. 286
  27. 583
  28. 1056
  29. 506
  30. 407
  31. 231
  32. 451
  33. 484
  34. 1056
  35. 825
  36. 792
  37. 649
  38. 1089
  39. 1232
  40. 1067

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