← The leapfrog sum trick lesson New set →

Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 455 · 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, 5, 7, 12, 19, 31, 50, 81, 131, 212. What is 11 × the 7th number?
  2. 2.7 + 2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 =
  3. 3.Leapfrog list (each number is the sum of the two before it): 6, 5, 11, 16, 27, 43, 70, 113, 183, 296. What is 11 × the 7th number?
  4. 4.A leapfrog list starts 8, 6 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): 1, 1, 2, 3, 5, 8, 13, 21, 34, 55. What is 11 × the 7th number?
  6. 6.9 + 9 + 18 + 27 + 45 + 72 + 117 + 189 + 306 + 495 =
  7. 7.2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 =
  8. 8.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?
  9. 9.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?
  10. 10.Leapfrog list (each number is the sum of the two before it): 9, 7, 16, 23, 39, 62, 101, 163, 264, 427. What is 11 × the 7th number?
  11. 11.Leapfrog list (each number is the sum of the two before it): 8, 3, 11, 14, 25, 39, 64, 103, 167, 270. What is 11 × the 7th number?
  12. 12.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?
  13. 13.Leapfrog list (each number is the sum of the two before it): 6, 4, 10, 14, 24, 38, 62, 100, 162, 262. What is 11 × the 7th number?
  14. 14.6 + 3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 =
  15. 15.6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 + 225 + 364 =
  16. 16.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?
  17. 17.3 + 3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 =
  18. 18.8 + 4 + 12 + 16 + 28 + 44 + 72 + 116 + 188 + 304 =
  19. 19.A leapfrog list starts 7, 7 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, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  21. 21.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?
  22. 22.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?
  23. 23.3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 + 369 =
  24. 24.Leapfrog list (each number is the sum of the two before it): 4, 6, 10, 16, 26, 42, 68, 110, 178, 288. What is 11 × the 7th number?
  25. 25.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?
  26. 26.Leapfrog list (each number is the sum of the two before it): 6, 7, 13, 20, 33, 53, 86, 139, 225, 364. What is 11 × the 7th number?
  27. 27.A leapfrog list starts 5, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  28. 28.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?
  29. 29.3 + 1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 =
  30. 30.2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 + 348 =
  31. 31.Leapfrog list (each number is the sum of the two before it): 7, 3, 10, 13, 23, 36, 59, 95, 154, 249. What is 11 × the 7th number?
  32. 32.7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 + 259 + 419 =
  33. 33.Leapfrog list (each number is the sum of the two before it): 8, 2, 10, 12, 22, 34, 56, 90, 146, 236. What is 11 × the 7th number?
  34. 34.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?
  35. 35.9 + 2 + 11 + 13 + 24 + 37 + 61 + 98 + 159 + 257 =
  36. 36.4 + 1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 =
  37. 37.9 + 6 + 15 + 21 + 36 + 57 + 93 + 150 + 243 + 393 =
  38. 38.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?
  39. 39.A leapfrog list starts 5, 2 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): 6, 3, 9, 12, 21, 33, 54, 87, 141, 228. What is 11 × the 7th number?

Answer key

  1. 550
  2. 561
  3. 770
  4. 968
  5. 143
  6. 1287
  7. 374
  8. 407
  9. 902
  10. 1111
  11. 704
  12. 473
  13. 682
  14. 594
  15. 946
  16. 594
  17. 429
  18. 792
  19. 1001
  20. 649
  21. 792
  22. 847
  23. 957
  24. 748
  25. 286
  26. 946
  27. 715
  28. 1177
  29. 253
  30. 902
  31. 649
  32. 1089
  33. 616
  34. 231
  35. 671
  36. 308
  37. 1023
  38. 693
  39. 451
  40. 594

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