← The leapfrog sum trick lesson New set →

Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 13 · 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. 1.6 + 5 + 11 + 16 + 27 + 43 + 70 + 113 + 183 + 296 =
  2. 2.9 + 1 + 10 + 11 + 21 + 32 + 53 + 85 + 138 + 223 =
  3. 3.Leapfrog list (each number is the sum of the two before it): 3, 1, 4, 5, 9, 14, 23, 37, 60, 97. What is 11 × the 7th number?
  4. 4.8 + 4 + 12 + 16 + 28 + 44 + 72 + 116 + 188 + 304 =
  5. 5.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?
  6. 6.5 + 1 + 6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 =
  7. 7.Leapfrog list (each number is the sum of the two before it): 1, 7, 8, 15, 23, 38, 61, 99, 160, 259. What is 11 × the 7th number?
  8. 8.7 + 2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 =
  9. 9.9 + 6 + 15 + 21 + 36 + 57 + 93 + 150 + 243 + 393 =
  10. 10.1 + 6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 + 225 =
  11. 11.7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 + 453 =
  12. 12.6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 + 267 + 432 =
  13. 13.A leapfrog list starts 3, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  14. 14.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?
  15. 15.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?
  16. 16.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?
  17. 17.A leapfrog list starts 7, 4 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, 9 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): 2, 5, 7, 12, 19, 31, 50, 81, 131, 212. What is 11 × the 7th number?
  20. 20.3 + 1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 =
  21. 21.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?
  22. 22.6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 + 398 =
  23. 23.3 + 2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 =
  24. 24.A leapfrog list starts 4, 1 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 9, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  26. 26.1 + 1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 =
  27. 27.6 + 3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 =
  28. 28.9 + 5 + 14 + 19 + 33 + 52 + 85 + 137 + 222 + 359 =
  29. 29.4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 + 199 + 322 =
  30. 30.A leapfrog list starts 2, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  31. 31.8 + 5 + 13 + 18 + 31 + 49 + 80 + 129 + 209 + 338 =
  32. 32.Leapfrog list (each number is the sum of the two before it): 9, 4, 13, 17, 30, 47, 77, 124, 201, 325. What is 11 × the 7th number?
  33. 33.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?
  34. 34.A leapfrog list starts 9, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  35. 35.3 + 7 + 10 + 17 + 27 + 44 + 71 + 115 + 186 + 301 =
  36. 36.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?
  37. 37.Leapfrog list (each number is the sum of the two before it): 9, 9, 18, 27, 45, 72, 117, 189, 306, 495. What is 11 × the 7th number?
  38. 38.A leapfrog list starts 5, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  39. 39.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?
  40. 40.Leapfrog list (each number is the sum of the two before it): 7, 6, 13, 19, 32, 51, 83, 134, 217, 351. What is 11 × the 7th number?

Answer key

  1. 770
  2. 583
  3. 253
  4. 792
  5. 1034
  6. 363
  7. 671
  8. 561
  9. 1023
  10. 583
  11. 1177
  12. 1122
  13. 693
  14. 1001
  15. 869
  16. 825
  17. 737
  18. 1287
  19. 550
  20. 253
  21. 1023
  22. 1034
  23. 341
  24. 308
  25. 671
  26. 143
  27. 594
  28. 935
  29. 836
  30. 198
  31. 880
  32. 847
  33. 418
  34. 759
  35. 781
  36. 374
  37. 1287
  38. 627
  39. 957
  40. 913

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