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Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 25 · 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 9, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  2. 2.A leapfrog list starts 8, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  3. 3.4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 + 356 =
  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.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?
  6. 6.4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 + 254 =
  7. 7.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?
  8. 8.A leapfrog list starts 3, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  9. 9.Leapfrog list (each number is the sum of the two before it): 6, 5, 11, 16, 27, 43, 70, 113, 183, 296. What is 11 × the 7th number?
  10. 10.A leapfrog list starts 3, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  11. 11.5 + 1 + 6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 =
  12. 12.8 + 5 + 13 + 18 + 31 + 49 + 80 + 129 + 209 + 338 =
  13. 13.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?
  14. 14.2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 =
  15. 15.6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 + 267 + 432 =
  16. 16.8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 + 474 =
  17. 17.Leapfrog list (each number is the sum of the two before it): 4, 1, 5, 6, 11, 17, 28, 45, 73, 118. What is 11 × the 7th number?
  18. 18.A leapfrog list starts 6, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  19. 19.9 + 7 + 16 + 23 + 39 + 62 + 101 + 163 + 264 + 427 =
  20. 20.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?
  21. 21.2 + 6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 =
  22. 22.8 + 8 + 16 + 24 + 40 + 64 + 104 + 168 + 272 + 440 =
  23. 23.7 + 3 + 10 + 13 + 23 + 36 + 59 + 95 + 154 + 249 =
  24. 24.Leapfrog list (each number is the sum of the two before it): 8, 7, 15, 22, 37, 59, 96, 155, 251, 406. What is 11 × the 7th number?
  25. 25.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?
  26. 26.Leapfrog list (each number is the sum of the two before it): 1, 5, 6, 11, 17, 28, 45, 73, 118, 191. What is 11 × the 7th number?
  27. 27.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?
  28. 28.7 + 7 + 14 + 21 + 35 + 56 + 91 + 147 + 238 + 385 =
  29. 29.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?
  30. 30.Leapfrog list (each number is the sum of the two before it): 7, 9, 16, 25, 41, 66, 107, 173, 280, 453. What is 11 × the 7th number?
  31. 31.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?
  32. 32.3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 + 199 =
  33. 33.3 + 1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 =
  34. 34.1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 + 327 =
  35. 35.Leapfrog list (each number is the sum of the two before it): 2, 7, 9, 16, 25, 41, 66, 107, 173, 280. What is 11 × the 7th number?
  36. 36.Leapfrog list (each number is the sum of the two before it): 2, 3, 5, 8, 13, 21, 34, 55, 89, 144. What is 11 × the 7th number?
  37. 37.8 + 6 + 14 + 20 + 34 + 54 + 88 + 142 + 230 + 372 =
  38. 38.9 + 8 + 17 + 25 + 42 + 67 + 109 + 176 + 285 + 461 =
  39. 39.2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 + 178 =
  40. 40.A leapfrog list starts 3, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?

Answer key

  1. 583
  2. 880
  3. 924
  4. 231
  5. 792
  6. 660
  7. 561
  8. 517
  9. 770
  10. 693
  11. 363
  12. 880
  13. 539
  14. 726
  15. 1122
  16. 1232
  17. 308
  18. 1034
  19. 1111
  20. 462
  21. 638
  22. 1144
  23. 649
  24. 1056
  25. 781
  26. 495
  27. 473
  28. 1001
  29. 1023
  30. 1177
  31. 253
  32. 517
  33. 253
  34. 847
  35. 726
  36. 374
  37. 968
  38. 1199
  39. 462
  40. 605

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