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.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?
- 2.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?
- 3.Leapfrog list (each number is the sum of the two before it): 1, 6, 7, 13, 20, 33, 53, 86, 139, 225. What is 11 × the 7th number?
- 4.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?
- 5.A leapfrog list starts 4, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 6.8 + 8 + 16 + 24 + 40 + 64 + 104 + 168 + 272 + 440 =
- 7.7 + 7 + 14 + 21 + 35 + 56 + 91 + 147 + 238 + 385 =
- 8.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?
- 9.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?
- 10.2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 + 348 =
- 11.1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 =
- 12.Leapfrog list (each number is the sum of the two before it): 3, 5, 8, 13, 21, 34, 55, 89, 144, 233. What is 11 × the 7th number?
- 13.3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 + 199 =
- 14.4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 + 178 + 288 =
- 15.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?
- 16.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?
- 17.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?
- 18.1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 =
- 19.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?
- 20.A leapfrog list starts 9, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 21.6 + 3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 =
- 22.8 + 3 + 11 + 14 + 25 + 39 + 64 + 103 + 167 + 270 =
- 23.2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 =
- 24.Leapfrog list (each number is the sum of the two before it): 6, 9, 15, 24, 39, 63, 102, 165, 267, 432. What is 11 × the 7th number?
- 25.2 + 1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 =
- 26.Leapfrog list (each number is the sum of the two before it): 4, 9, 13, 22, 35, 57, 92, 149, 241, 390. What is 11 × the 7th number?
- 27.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?
- 28.1 + 8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 =
- 29.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?
- 30.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?
- 31.6 + 4 + 10 + 14 + 24 + 38 + 62 + 100 + 162 + 262 =
- 32.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?
- 33.8 + 6 + 14 + 20 + 34 + 54 + 88 + 142 + 230 + 372 =
- 34.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?
- 35.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?
- 36.2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 + 178 =
- 37.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?
- 38.2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 =
- 39.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?
- 40.A leapfrog list starts 7, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
Answer key
- 308
- 407
- 583
- 836
- 396
- 1144
- 1001
- 462
- 286
- 902
- 495
- 605
- 517
- 748
- 858
- 484
- 407
- 407
- 495
- 671
- 594
- 704
- 374
- 1122
- 198
- 1012
- 671
- 759
- 429
- 880
- 682
- 1287
- 968
- 451
- 1177
- 462
- 473
- 726
- 253
- 649
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