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Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 671 · 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.A leapfrog list starts 5, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  2. 2.Leapfrog list (each number is the sum of the two before it): 4, 4, 8, 12, 20, 32, 52, 84, 136, 220. What is 11 × the 7th number?
  3. 3.1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 + 259 =
  4. 4.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?
  5. 5.2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 =
  6. 6.3 + 2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 =
  7. 7.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?
  8. 8.6 + 3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 =
  9. 9.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?
  10. 10.A leapfrog list starts 6, 6 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): 4, 3, 7, 10, 17, 27, 44, 71, 115, 186. What is 11 × the 7th number?
  12. 12.A leapfrog list starts 2, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  13. 13.8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 + 474 =
  14. 14.7 + 1 + 8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 =
  15. 15.1 + 1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 =
  16. 16.A leapfrog list starts 3, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  17. 17.Leapfrog list (each number is the sum of the two before it): 5, 6, 11, 17, 28, 45, 73, 118, 191, 309. What is 11 × the 7th number?
  18. 18.5 + 4 + 9 + 13 + 22 + 35 + 57 + 92 + 149 + 241 =
  19. 19.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?
  20. 20.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?
  21. 21.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?
  22. 22.Leapfrog list (each number is the sum of the two before it): 3, 9, 12, 21, 33, 54, 87, 141, 228, 369. What is 11 × the 7th number?
  23. 23.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?
  24. 24.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?
  25. 25.3 + 1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 =
  26. 26.1 + 6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 + 225 =
  27. 27.A leapfrog list starts 5, 9 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 1, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  29. 29.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?
  30. 30.A leapfrog list starts 6, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  31. 31.4 + 1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 =
  32. 32.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?
  33. 33.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?
  34. 34.8 + 6 + 14 + 20 + 34 + 54 + 88 + 142 + 230 + 372 =
  35. 35.A leapfrog list starts 8, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  36. 36.9 + 3 + 12 + 15 + 27 + 42 + 69 + 111 + 180 + 291 =
  37. 37.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?
  38. 38.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?
  39. 39.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?
  40. 40.3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 + 233 =

Answer key

  1. 363
  2. 572
  3. 671
  4. 231
  5. 726
  6. 341
  7. 792
  8. 594
  9. 1012
  10. 858
  11. 484
  12. 286
  13. 1232
  14. 473
  15. 143
  16. 781
  17. 803
  18. 627
  19. 1001
  20. 957
  21. 319
  22. 957
  23. 583
  24. 1177
  25. 253
  26. 583
  27. 1067
  28. 143
  29. 671
  30. 946
  31. 308
  32. 913
  33. 253
  34. 968
  35. 792
  36. 759
  37. 561
  38. 715
  39. 847
  40. 605

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