Leapfrog Sum Trick Worksheet
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
- 1.8 + 5 + 13 + 18 + 31 + 49 + 80 + 129 + 209 + 338 =
- 2.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?
- 3.2 + 1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 =
- 4.4 + 1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 =
- 5.3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 + 233 =
- 6.6 + 2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 =
- 7.3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 + 199 =
- 8.A leapfrog list starts 4, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 9.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?
- 10.9 + 8 + 17 + 25 + 42 + 67 + 109 + 176 + 285 + 461 =
- 11.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?
- 12.2 + 2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 =
- 13.Leapfrog list (each number is the sum of the two before it): 9, 2, 11, 13, 24, 37, 61, 98, 159, 257. What is 11 × the 7th number?
- 14.Leapfrog list (each number is the sum of the two before it): 4, 5, 9, 14, 23, 37, 60, 97, 157, 254. What is 11 × the 7th number?
- 15.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?
- 16.4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 + 178 + 288 =
- 17.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?
- 18.A leapfrog list starts 1, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 19.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?
- 20.7 + 6 + 13 + 19 + 32 + 51 + 83 + 134 + 217 + 351 =
- 21.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?
- 22.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?
- 23.5 + 2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 =
- 24.A leapfrog list starts 1, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 25.A leapfrog list starts 2, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 26.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?
- 27.1 + 1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 =
- 28.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?
- 29.2 + 6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 =
- 30.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?
- 31.2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 + 314 =
- 32.Leapfrog list (each number is the sum of the two before it): 5, 5, 10, 15, 25, 40, 65, 105, 170, 275. What is 11 × the 7th number?
- 33.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?
- 34.Leapfrog list (each number is the sum of the two before it): 4, 7, 11, 18, 29, 47, 76, 123, 199, 322. What is 11 × the 7th number?
- 35.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?
- 36.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?
- 37.Leapfrog list (each number is the sum of the two before it): 1, 1, 2, 3, 5, 8, 13, 21, 34, 55. What is 11 × the 7th number?
- 38.Leapfrog list (each number is the sum of the two before it): 7, 1, 8, 9, 17, 26, 43, 69, 112, 181. What is 11 × the 7th number?
- 39.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?
- 40.5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 + 309 =
Answer key
- 880
- 748
- 198
- 308
- 605
- 506
- 517
- 1012
- 638
- 1199
- 814
- 286
- 671
- 660
- 363
- 748
- 506
- 495
- 880
- 913
- 286
- 253
- 451
- 143
- 198
- 462
- 143
- 484
- 638
- 924
- 814
- 715
- 979
- 836
- 561
- 407
- 143
- 473
- 1056
- 803
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