← The leapfrog sum trick lesson New set →

Leapfrog Sum Trick Worksheet

Maths tricks trick 25: The leapfrog sum trick · Set 354 · 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, 9 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, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  3. 3.8 + 1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 =
  4. 4.Leapfrog list (each number is the sum of the two before it): 9, 4, 13, 17, 30, 47, 77, 124, 201, 325. What is 11 × the 7th number?
  5. 5.6 + 4 + 10 + 14 + 24 + 38 + 62 + 100 + 162 + 262 =
  6. 6.1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 =
  7. 7.A leapfrog list starts 9, 8 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 6, 3 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): 3, 2, 5, 7, 12, 19, 31, 50, 81, 131. What is 11 × the 7th number?
  10. 10.8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 + 474 =
  11. 11.1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 =
  12. 12.Leapfrog list (each number is the sum of the two before it): 2, 5, 7, 12, 19, 31, 50, 81, 131, 212. What is 11 × the 7th number?
  13. 13.6 + 5 + 11 + 16 + 27 + 43 + 70 + 113 + 183 + 296 =
  14. 14.4 + 2 + 6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 =
  15. 15.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?
  16. 16.A leapfrog list starts 9, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  17. 17.4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 + 356 =
  18. 18.8 + 5 + 13 + 18 + 31 + 49 + 80 + 129 + 209 + 338 =
  19. 19.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?
  20. 20.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?
  21. 21.3 + 1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 =
  22. 22.Leapfrog list (each number is the sum of the two before it): 9, 5, 14, 19, 33, 52, 85, 137, 222, 359. What is 11 × the 7th number?
  23. 23.5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 + 233 + 377 =
  24. 24.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?
  25. 25.5 + 4 + 9 + 13 + 22 + 35 + 57 + 92 + 149 + 241 =
  26. 26.Leapfrog list (each number is the sum of the two before it): 2, 1, 3, 4, 7, 11, 18, 29, 47, 76. What is 11 × the 7th number?
  27. 27.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?
  28. 28.Leapfrog list (each number is the sum of the two before it): 9, 3, 12, 15, 27, 42, 69, 111, 180, 291. What is 11 × the 7th number?
  29. 29.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?
  30. 30.A leapfrog list starts 2, 4 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): 9, 8, 17, 25, 42, 67, 109, 176, 285, 461. What is 11 × the 7th number?
  32. 32.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?
  33. 33.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?
  34. 34.1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 =
  35. 35.8 + 6 + 14 + 20 + 34 + 54 + 88 + 142 + 230 + 372 =
  36. 36.3 + 2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 =
  37. 37.9 + 1 + 10 + 11 + 21 + 32 + 53 + 85 + 138 + 223 =
  38. 38.Leapfrog list (each number is the sum of the two before it): 2, 9, 11, 20, 31, 51, 82, 133, 215, 348. What is 11 × the 7th number?
  39. 39.A leapfrog list starts 5, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
  40. 40.A leapfrog list starts 1, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?

Answer key

  1. 1067
  2. 1144
  3. 528
  4. 847
  5. 682
  6. 495
  7. 1199
  8. 594
  9. 341
  10. 1232
  11. 319
  12. 550
  13. 770
  14. 396
  15. 308
  16. 1023
  17. 924
  18. 880
  19. 1034
  20. 484
  21. 253
  22. 935
  23. 979
  24. 1287
  25. 627
  26. 198
  27. 583
  28. 759
  29. 286
  30. 462
  31. 1199
  32. 341
  33. 770
  34. 231
  35. 968
  36. 341
  37. 583
  38. 902
  39. 803
  40. 407

Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks