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Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 222 · 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. 1.9 + 6 + 15 + 21 + 36 + 57 + 93 + 150 + 243 + 393 =
  2. 2.Leapfrog list (each number is the sum of the two before it): 4, 8, 12, 20, 32, 52, 84, 136, 220, 356. What is 11 × the 7th number?
  3. 3.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?
  4. 4.Leapfrog list (each number is the sum of the two before it): 3, 3, 6, 9, 15, 24, 39, 63, 102, 165. What is 11 × the 7th number?
  5. 5.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?
  6. 6.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?
  7. 7.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?
  8. 8.3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 + 233 =
  9. 9.2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 =
  10. 10.A leapfrog list starts 5, 3 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): 2, 8, 10, 18, 28, 46, 74, 120, 194, 314. What is 11 × the 7th number?
  12. 12.1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 =
  13. 13.4 + 9 + 13 + 22 + 35 + 57 + 92 + 149 + 241 + 390 =
  14. 14.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?
  15. 15.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?
  16. 16.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?
  17. 17.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?
  18. 18.A leapfrog list starts 7, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  19. 19.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?
  20. 20.Leapfrog list (each number is the sum of the two before it): 8, 5, 13, 18, 31, 49, 80, 129, 209, 338. What is 11 × the 7th number?
  21. 21.5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 + 309 =
  22. 22.Leapfrog list (each number is the sum of the two before it): 9, 1, 10, 11, 21, 32, 53, 85, 138, 223. What is 11 × the 7th number?
  23. 23.A leapfrog list starts 4, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  24. 24.6 + 4 + 10 + 14 + 24 + 38 + 62 + 100 + 162 + 262 =
  25. 25.1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 =
  26. 26.9 + 5 + 14 + 19 + 33 + 52 + 85 + 137 + 222 + 359 =
  27. 27.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?
  28. 28.2 + 2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 =
  29. 29.Leapfrog list (each number is the sum of the two before it): 7, 4, 11, 15, 26, 41, 67, 108, 175, 283. What is 11 × the 7th number?
  30. 30.4 + 2 + 6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 =
  31. 31.A leapfrog list starts 3, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  32. 32.A leapfrog list starts 8, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  33. 33.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?
  34. 34.2 + 1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 =
  35. 35.3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 + 267 =
  36. 36.3 + 1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 =
  37. 37.A leapfrog list starts 5, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  38. 38.4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 + 254 =
  39. 39.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?
  40. 40.9 + 7 + 16 + 23 + 39 + 62 + 101 + 163 + 264 + 427 =

Answer key

  1. 1023
  2. 924
  3. 858
  4. 429
  5. 253
  6. 671
  7. 869
  8. 605
  9. 550
  10. 539
  11. 814
  12. 231
  13. 1012
  14. 957
  15. 671
  16. 627
  17. 1287
  18. 913
  19. 968
  20. 880
  21. 803
  22. 583
  23. 484
  24. 682
  25. 407
  26. 935
  27. 792
  28. 286
  29. 737
  30. 396
  31. 341
  32. 1056
  33. 935
  34. 198
  35. 693
  36. 253
  37. 891
  38. 660
  39. 407
  40. 1111

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