← The leapfrog sum trick lesson New set →

Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 841 · 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. 1.2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 =
  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): 8, 9, 17, 26, 43, 69, 112, 181, 293, 474. What is 11 × the 7th number?
  4. 4.A leapfrog list starts 9, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  5. 5.8 + 6 + 14 + 20 + 34 + 54 + 88 + 142 + 230 + 372 =
  6. 6.Leapfrog list (each number is the sum of the two before it): 5, 5, 10, 15, 25, 40, 65, 105, 170, 275. What is 11 × the 7th number?
  7. 7.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?
  8. 8.1 + 1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 =
  9. 9.6 + 1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 =
  10. 10.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?
  11. 11.2 + 6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 =
  12. 12.6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 + 225 + 364 =
  13. 13.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?
  14. 14.Leapfrog list (each number is the sum of the two before it): 2, 4, 6, 10, 16, 26, 42, 68, 110, 178. What is 11 × the 7th number?
  15. 15.4 + 1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 =
  16. 16.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?
  17. 17.4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 + 356 =
  18. 18.5 + 4 + 9 + 13 + 22 + 35 + 57 + 92 + 149 + 241 =
  19. 19.5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 + 343 =
  20. 20.Leapfrog list (each number is the sum of the two before it): 1, 3, 4, 7, 11, 18, 29, 47, 76, 123. What is 11 × the 7th number?
  21. 21.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?
  22. 22.6 + 6 + 12 + 18 + 30 + 48 + 78 + 126 + 204 + 330 =
  23. 23.Leapfrog list (each number is the sum of the two before it): 1, 9, 10, 19, 29, 48, 77, 125, 202, 327. What is 11 × the 7th number?
  24. 24.1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 =
  25. 25.5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 + 254 + 411 =
  26. 26.Leapfrog list (each number is the sum of the two before it): 5, 1, 6, 7, 13, 20, 33, 53, 86, 139. What is 11 × the 7th number?
  27. 27.3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 + 267 =
  28. 28.6 + 5 + 11 + 16 + 27 + 43 + 70 + 113 + 183 + 296 =
  29. 29.8 + 2 + 10 + 12 + 22 + 34 + 56 + 90 + 146 + 236 =
  30. 30.1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 =
  31. 31.7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 + 259 + 419 =
  32. 32.9 + 4 + 13 + 17 + 30 + 47 + 77 + 124 + 201 + 325 =
  33. 33.4 + 2 + 6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 =
  34. 34.A leapfrog list starts 9, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  35. 35.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?
  36. 36.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?
  37. 37.8 + 5 + 13 + 18 + 31 + 49 + 80 + 129 + 209 + 338 =
  38. 38.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?
  39. 39.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?
  40. 40.8 + 1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 =

Answer key

  1. 726
  2. 583
  3. 1232
  4. 847
  5. 968
  6. 715
  7. 671
  8. 143
  9. 418
  10. 935
  11. 638
  12. 946
  13. 473
  14. 462
  15. 308
  16. 1287
  17. 924
  18. 627
  19. 891
  20. 319
  21. 308
  22. 858
  23. 847
  24. 407
  25. 1067
  26. 363
  27. 693
  28. 770
  29. 616
  30. 495
  31. 1089
  32. 847
  33. 396
  34. 583
  35. 583
  36. 836
  37. 880
  38. 638
  39. 407
  40. 528

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