← The leapfrog sum trick lesson New set →

Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 557 · 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): 2, 7, 9, 16, 25, 41, 66, 107, 173, 280. What is 11 × the 7th number?
  2. 2.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?
  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 + 8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 =
  5. 5.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?
  6. 6.6 + 6 + 12 + 18 + 30 + 48 + 78 + 126 + 204 + 330 =
  7. 7.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?
  8. 8.7 + 4 + 11 + 15 + 26 + 41 + 67 + 108 + 175 + 283 =
  9. 9.5 + 1 + 6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 =
  10. 10.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?
  11. 11.Leapfrog list (each number is the sum of the two before it): 7, 2, 9, 11, 20, 31, 51, 82, 133, 215. 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. 13.9 + 5 + 14 + 19 + 33 + 52 + 85 + 137 + 222 + 359 =
  14. 14.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?
  15. 15.A leapfrog list starts 1, 4 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): 2, 6, 8, 14, 22, 36, 58, 94, 152, 246. What is 11 × the 7th number?
  17. 17.A leapfrog list starts 3, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  18. 18.A leapfrog list starts 9, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  19. 19.A leapfrog list starts 8, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  20. 20.A leapfrog list starts 7, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  21. 21.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?
  22. 22.5 + 4 + 9 + 13 + 22 + 35 + 57 + 92 + 149 + 241 =
  23. 23.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?
  24. 24.A leapfrog list starts 6, 3 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 7, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  26. 26.Leapfrog list (each number is the sum of the two before it): 9, 2, 11, 13, 24, 37, 61, 98, 159, 257. What is 11 × the 7th number?
  27. 27.2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 + 348 =
  28. 28.A leapfrog list starts 4, 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 9, 9 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): 4, 3, 7, 10, 17, 27, 44, 71, 115, 186. What is 11 × the 7th number?
  31. 31.2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 =
  32. 32.9 + 6 + 15 + 21 + 36 + 57 + 93 + 150 + 243 + 393 =
  33. 33.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?
  34. 34.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?
  35. 35.2 + 2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 =
  36. 36.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?
  37. 37.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?
  38. 38.Leapfrog list (each number is the sum of the two before it): 6, 6, 12, 18, 30, 48, 78, 126, 204, 330. What is 11 × the 7th number?
  39. 39.5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 + 254 + 411 =
  40. 40.A leapfrog list starts 2, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?

Answer key

  1. 726
  2. 770
  3. 583
  4. 759
  5. 671
  6. 858
  7. 1001
  8. 737
  9. 363
  10. 957
  11. 561
  12. 473
  13. 935
  14. 473
  15. 407
  16. 638
  17. 253
  18. 1111
  19. 528
  20. 1089
  21. 704
  22. 627
  23. 506
  24. 594
  25. 1177
  26. 671
  27. 902
  28. 836
  29. 1287
  30. 484
  31. 550
  32. 1023
  33. 198
  34. 748
  35. 286
  36. 814
  37. 792
  38. 858
  39. 1067
  40. 374

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