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, 8, 12, 20, 32, 52, 84, 136, 220, 356. What is 11 × the 7th number?
- 2.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?
- 3.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?
- 4.5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 + 343 =
- 5.A leapfrog list starts 2, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 6.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?
- 7.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?
- 8.4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 + 254 =
- 9.7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 + 453 =
- 10.Leapfrog list (each number is the sum of the two before it): 5, 6, 11, 17, 28, 45, 73, 118, 191, 309. What is 11 × the 7th number?
- 11.1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 + 259 =
- 12.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?
- 13.6 + 4 + 10 + 14 + 24 + 38 + 62 + 100 + 162 + 262 =
- 14.1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 =
- 15.4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 + 199 + 322 =
- 16.6 + 3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 =
- 17.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?
- 18.3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 + 369 =
- 19.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?
- 20.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?
- 21.4 + 3 + 7 + 10 + 17 + 27 + 44 + 71 + 115 + 186 =
- 22.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?
- 23.Leapfrog list (each number is the sum of the two before it): 8, 1, 9, 10, 19, 29, 48, 77, 125, 202. What is 11 × the 7th number?
- 24.2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 =
- 25.Leapfrog list (each number is the sum of the two before it): 3, 8, 11, 19, 30, 49, 79, 128, 207, 335. What is 11 × the 7th number?
- 26.2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 =
- 27.A leapfrog list starts 7, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 28.4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 + 178 + 288 =
- 29.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?
- 30.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?
- 31.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?
- 32.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?
- 33.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?
- 34.2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 =
- 35.1 + 8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 =
- 36.A leapfrog list starts 5, 1 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): 2, 9, 11, 20, 31, 51, 82, 133, 215, 348. What is 11 × the 7th number?
- 38.5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 + 233 + 377 =
- 39.1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 =
- 40.A leapfrog list starts 7, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
Answer key
- 924
- 462
- 1122
- 891
- 726
- 671
- 550
- 660
- 1177
- 803
- 671
- 1012
- 682
- 319
- 836
- 594
- 660
- 957
- 517
- 1177
- 484
- 231
- 528
- 374
- 869
- 726
- 473
- 748
- 957
- 605
- 286
- 396
- 649
- 550
- 759
- 363
- 902
- 979
- 407
- 561
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