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Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 393 · 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 6, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  2. 2.2 + 6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 =
  3. 3.4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 + 199 + 322 =
  4. 4.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?
  5. 5.9 + 2 + 11 + 13 + 24 + 37 + 61 + 98 + 159 + 257 =
  6. 6.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?
  7. 7.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?
  8. 8.A leapfrog list starts 1, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  9. 9.4 + 9 + 13 + 22 + 35 + 57 + 92 + 149 + 241 + 390 =
  10. 10.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?
  11. 11.3 + 7 + 10 + 17 + 27 + 44 + 71 + 115 + 186 + 301 =
  12. 12.7 + 7 + 14 + 21 + 35 + 56 + 91 + 147 + 238 + 385 =
  13. 13.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?
  14. 14.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?
  15. 15.Leapfrog list (each number is the sum of the two before it): 5, 8, 13, 21, 34, 55, 89, 144, 233, 377. What is 11 × the 7th number?
  16. 16.A leapfrog list starts 6, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  17. 17.1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 + 259 =
  18. 18.Leapfrog list (each number is the sum of the two before it): 1, 8, 9, 17, 26, 43, 69, 112, 181, 293. What is 11 × the 7th number?
  19. 19.6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 + 398 =
  20. 20.Leapfrog list (each number is the sum of the two before it): 6, 4, 10, 14, 24, 38, 62, 100, 162, 262. What is 11 × the 7th number?
  21. 21.3 + 1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 =
  22. 22.A leapfrog list starts 2, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  23. 23.A leapfrog list starts 1, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  24. 24.4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 + 254 =
  25. 25.6 + 3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 =
  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.A leapfrog list starts 8, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  28. 28.Leapfrog list (each number is the sum of the two before it): 9, 8, 17, 25, 42, 67, 109, 176, 285, 461. What is 11 × the 7th number?
  29. 29.5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 + 233 + 377 =
  30. 30.A leapfrog list starts 5, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  31. 31.1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 + 327 =
  32. 32.5 + 2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 =
  33. 33.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?
  34. 34.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?
  35. 35.5 + 5 + 10 + 15 + 25 + 40 + 65 + 105 + 170 + 275 =
  36. 36.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?
  37. 37.2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 + 314 =
  38. 38.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?
  39. 39.Leapfrog list (each number is the sum of the two before it): 8, 1, 9, 10, 19, 29, 48, 77, 125, 202. What is 11 × the 7th number?
  40. 40.6 + 4 + 10 + 14 + 24 + 38 + 62 + 100 + 162 + 262 =

Answer key

  1. 770
  2. 638
  3. 836
  4. 473
  5. 671
  6. 286
  7. 1111
  8. 759
  9. 1012
  10. 792
  11. 781
  12. 1001
  13. 671
  14. 913
  15. 979
  16. 1122
  17. 671
  18. 759
  19. 1034
  20. 682
  21. 253
  22. 638
  23. 231
  24. 660
  25. 594
  26. 363
  27. 616
  28. 1199
  29. 979
  30. 451
  31. 847
  32. 451
  33. 1177
  34. 748
  35. 715
  36. 1023
  37. 814
  38. 847
  39. 528
  40. 682

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