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): 3, 4, 7, 11, 18, 29, 47, 76, 123, 199. What is 11 × the 7th number?
- 2.2 + 2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 =
- 3.6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 + 398 =
- 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 2, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 6.6 + 5 + 11 + 16 + 27 + 43 + 70 + 113 + 183 + 296 =
- 7.2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 + 314 =
- 8.5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 + 233 + 377 =
- 9.2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 =
- 10.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?
- 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?
- 12.3 + 3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 =
- 13.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?
- 14.3 + 2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 =
- 15.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?
- 16.5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 + 254 + 411 =
- 17.3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 + 199 =
- 18.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?
- 19.9 + 6 + 15 + 21 + 36 + 57 + 93 + 150 + 243 + 393 =
- 20.5 + 4 + 9 + 13 + 22 + 35 + 57 + 92 + 149 + 241 =
- 21.Leapfrog list (each number is the sum of the two before it): 8, 2, 10, 12, 22, 34, 56, 90, 146, 236. What is 11 × the 7th number?
- 22.3 + 1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 =
- 23.Leapfrog list (each number is the sum of the two before it): 5, 2, 7, 9, 16, 25, 41, 66, 107, 173. What is 11 × the 7th number?
- 24.Leapfrog list (each number is the sum of the two before it): 3, 7, 10, 17, 27, 44, 71, 115, 186, 301. What is 11 × the 7th number?
- 25.7 + 5 + 12 + 17 + 29 + 46 + 75 + 121 + 196 + 317 =
- 26.Leapfrog list (each number is the sum of the two before it): 8, 3, 11, 14, 25, 39, 64, 103, 167, 270. What is 11 × the 7th number?
- 27.A leapfrog list starts 6, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 28.Leapfrog list (each number is the sum of the two before it): 3, 9, 12, 21, 33, 54, 87, 141, 228, 369. What is 11 × the 7th number?
- 29.1 + 8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 =
- 30.A leapfrog list starts 1, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 31.Leapfrog list (each number is the sum of the two before it): 7, 3, 10, 13, 23, 36, 59, 95, 154, 249. What is 11 × the 7th number?
- 32.8 + 2 + 10 + 12 + 22 + 34 + 56 + 90 + 146 + 236 =
- 33.8 + 8 + 16 + 24 + 40 + 64 + 104 + 168 + 272 + 440 =
- 34.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?
- 35.2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 =
- 36.6 + 6 + 12 + 18 + 30 + 48 + 78 + 126 + 204 + 330 =
- 37.5 + 2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 =
- 38.7 + 7 + 14 + 21 + 35 + 56 + 91 + 147 + 238 + 385 =
- 39.Leapfrog list (each number is the sum of the two before it): 6, 8, 14, 22, 36, 58, 94, 152, 246, 398. What is 11 × the 7th number?
- 40.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?
Answer key
- 517
- 286
- 1034
- 836
- 550
- 770
- 814
- 979
- 726
- 913
- 814
- 429
- 1067
- 341
- 792
- 1067
- 517
- 495
- 1023
- 627
- 616
- 253
- 451
- 781
- 825
- 704
- 946
- 957
- 759
- 319
- 649
- 616
- 1144
- 495
- 374
- 858
- 451
- 1001
- 1034
- 550
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