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Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 837 · 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 1, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  2. 2.6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 + 398 =
  3. 3.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?
  4. 4.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?
  5. 5.3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 + 369 =
  6. 6.A leapfrog list starts 4, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  7. 7.A leapfrog list starts 2, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  8. 8.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?
  9. 9.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?
  10. 10.A leapfrog list starts 6, 4 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): 3, 1, 4, 5, 9, 14, 23, 37, 60, 97. What is 11 × the 7th number?
  12. 12.Leapfrog list (each number is the sum of the two before it): 3, 2, 5, 7, 12, 19, 31, 50, 81, 131. What is 11 × the 7th number?
  13. 13.A leapfrog list starts 2, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  14. 14.5 + 2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 =
  15. 15.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?
  16. 16.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?
  17. 17.7 + 2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 =
  18. 18.8 + 8 + 16 + 24 + 40 + 64 + 104 + 168 + 272 + 440 =
  19. 19.A leapfrog list starts 1, 3 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 3, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  21. 21.7 + 7 + 14 + 21 + 35 + 56 + 91 + 147 + 238 + 385 =
  22. 22.A leapfrog list starts 7, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  23. 23.Leapfrog list (each number is the sum of the two before it): 6, 2, 8, 10, 18, 28, 46, 74, 120, 194. What is 11 × the 7th number?
  24. 24.8 + 2 + 10 + 12 + 22 + 34 + 56 + 90 + 146 + 236 =
  25. 25.A leapfrog list starts 9, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  26. 26.3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 + 233 =
  27. 27.3 + 2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 =
  28. 28.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?
  29. 29.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?
  30. 30.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?
  31. 31.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?
  32. 32.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?
  33. 33.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?
  34. 34.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?
  35. 35.6 + 5 + 11 + 16 + 27 + 43 + 70 + 113 + 183 + 296 =
  36. 36.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?
  37. 37.Leapfrog list (each number is the sum of the two before it): 5, 4, 9, 13, 22, 35, 57, 92, 149, 241. What is 11 × the 7th number?
  38. 38.2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 =
  39. 39.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?
  40. 40.8 + 4 + 12 + 16 + 28 + 44 + 72 + 116 + 188 + 304 =

Answer key

  1. 583
  2. 1034
  3. 1111
  4. 649
  5. 957
  6. 660
  7. 902
  8. 231
  9. 858
  10. 682
  11. 253
  12. 341
  13. 814
  14. 451
  15. 286
  16. 1023
  17. 561
  18. 1144
  19. 319
  20. 253
  21. 1001
  22. 561
  23. 506
  24. 616
  25. 935
  26. 605
  27. 341
  28. 737
  29. 286
  30. 418
  31. 638
  32. 583
  33. 748
  34. 374
  35. 770
  36. 748
  37. 627
  38. 726
  39. 561
  40. 792

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