← The leapfrog sum trick lesson New set →

Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 961 · 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): 6, 2, 8, 10, 18, 28, 46, 74, 120, 194. What is 11 × the 7th number?
  2. 2.2 + 2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 =
  3. 3.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?
  4. 4.Leapfrog list (each number is the sum of the two before it): 3, 3, 6, 9, 15, 24, 39, 63, 102, 165. What is 11 × the 7th number?
  5. 5.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?
  6. 6.7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 + 259 + 419 =
  7. 7.8 + 1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 =
  8. 8.Leapfrog list (each number is the sum of the two before it): 1, 2, 3, 5, 8, 13, 21, 34, 55, 89. What is 11 × the 7th number?
  9. 9.7 + 7 + 14 + 21 + 35 + 56 + 91 + 147 + 238 + 385 =
  10. 10.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?
  11. 11.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?
  12. 12.1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 =
  13. 13.6 + 4 + 10 + 14 + 24 + 38 + 62 + 100 + 162 + 262 =
  14. 14.9 + 7 + 16 + 23 + 39 + 62 + 101 + 163 + 264 + 427 =
  15. 15.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?
  16. 16.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?
  17. 17.1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 =
  18. 18.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?
  19. 19.9 + 5 + 14 + 19 + 33 + 52 + 85 + 137 + 222 + 359 =
  20. 20.8 + 4 + 12 + 16 + 28 + 44 + 72 + 116 + 188 + 304 =
  21. 21.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?
  22. 22.Leapfrog list (each number is the sum of the two before it): 2, 1, 3, 4, 7, 11, 18, 29, 47, 76. What is 11 × the 7th number?
  23. 23.8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 + 474 =
  24. 24.3 + 7 + 10 + 17 + 27 + 44 + 71 + 115 + 186 + 301 =
  25. 25.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?
  26. 26.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?
  27. 27.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?
  28. 28.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?
  29. 29.6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 + 398 =
  30. 30.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?
  31. 31.1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 =
  32. 32.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?
  33. 33.Leapfrog list (each number is the sum of the two before it): 2, 9, 11, 20, 31, 51, 82, 133, 215, 348. What is 11 × the 7th number?
  34. 34.Leapfrog list (each number is the sum of the two before it): 8, 5, 13, 18, 31, 49, 80, 129, 209, 338. What is 11 × the 7th number?
  35. 35.9 + 2 + 11 + 13 + 24 + 37 + 61 + 98 + 159 + 257 =
  36. 36.7 + 2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 =
  37. 37.Leapfrog list (each number is the sum of the two before it): 7, 8, 15, 23, 38, 61, 99, 160, 259, 419. What is 11 × the 7th number?
  38. 38.7 + 3 + 10 + 13 + 23 + 36 + 59 + 95 + 154 + 249 =
  39. 39.A leapfrog list starts 2, 6 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 3, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?

Answer key

  1. 506
  2. 286
  3. 726
  4. 429
  5. 473
  6. 1089
  7. 528
  8. 231
  9. 1001
  10. 539
  11. 143
  12. 231
  13. 682
  14. 1111
  15. 770
  16. 1012
  17. 495
  18. 407
  19. 935
  20. 792
  21. 1034
  22. 198
  23. 1232
  24. 781
  25. 869
  26. 231
  27. 1199
  28. 605
  29. 1034
  30. 825
  31. 319
  32. 913
  33. 902
  34. 880
  35. 671
  36. 561
  37. 1089
  38. 649
  39. 638
  40. 957

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