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): 8, 2, 10, 12, 22, 34, 56, 90, 146, 236. What is 11 × the 7th number?
- 2.Leapfrog list (each number is the sum of the two before it): 4, 4, 8, 12, 20, 32, 52, 84, 136, 220. What is 11 × the 7th number?
- 3.A leapfrog list starts 8, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 4.8 + 2 + 10 + 12 + 22 + 34 + 56 + 90 + 146 + 236 =
- 5.3 + 3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 =
- 6.A leapfrog list starts 9, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 7.2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 + 348 =
- 8.6 + 1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 =
- 9.2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 + 178 =
- 10.Leapfrog list (each number is the sum of the two before it): 6, 6, 12, 18, 30, 48, 78, 126, 204, 330. What is 11 × the 7th number?
- 11.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?
- 12.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?
- 13.A leapfrog list starts 5, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 14.A leapfrog list starts 5, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 15.2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 =
- 16.A leapfrog list starts 2, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 17.Leapfrog list (each number is the sum of the two before it): 3, 6, 9, 15, 24, 39, 63, 102, 165, 267. What is 11 × the 7th number?
- 18.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?
- 19.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?
- 20.7 + 6 + 13 + 19 + 32 + 51 + 83 + 134 + 217 + 351 =
- 21.2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 =
- 22.5 + 3 + 8 + 11 + 19 + 30 + 49 + 79 + 128 + 207 =
- 23.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?
- 24.A leapfrog list starts 1, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 25.4 + 3 + 7 + 10 + 17 + 27 + 44 + 71 + 115 + 186 =
- 26.3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 + 267 =
- 27.Leapfrog list (each number is the sum of the two before it): 8, 5, 13, 18, 31, 49, 80, 129, 209, 338. What is 11 × the 7th number?
- 28.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?
- 29.2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 + 314 =
- 30.Leapfrog list (each number is the sum of the two before it): 2, 8, 10, 18, 28, 46, 74, 120, 194, 314. What is 11 × the 7th number?
- 31.4 + 2 + 6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 =
- 32.5 + 4 + 9 + 13 + 22 + 35 + 57 + 92 + 149 + 241 =
- 33.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?
- 34.6 + 2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 =
- 35.4 + 1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 =
- 36.7 + 7 + 14 + 21 + 35 + 56 + 91 + 147 + 238 + 385 =
- 37.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?
- 38.4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 + 254 =
- 39.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?
- 40.3 + 1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 =
Answer key
- 616
- 572
- 528
- 616
- 429
- 759
- 902
- 418
- 462
- 858
- 231
- 671
- 715
- 891
- 550
- 638
- 693
- 506
- 253
- 913
- 726
- 539
- 858
- 759
- 484
- 693
- 880
- 649
- 814
- 814
- 396
- 627
- 286
- 506
- 308
- 1001
- 1023
- 660
- 143
- 253
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