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
- 1.7 + 2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 =
- 2.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?
- 3.A leapfrog list starts 3, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 4.1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 =
- 5.Leapfrog list (each number is the sum of the two before it): 8, 7, 15, 22, 37, 59, 96, 155, 251, 406. What is 11 × the 7th number?
- 6.Leapfrog list (each number is the sum of the two before it): 4, 3, 7, 10, 17, 27, 44, 71, 115, 186. What is 11 × the 7th number?
- 7.Leapfrog list (each number is the sum of the two before it): 1, 7, 8, 15, 23, 38, 61, 99, 160, 259. What is 11 × the 7th number?
- 8.A leapfrog list starts 6, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 9.5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 + 233 + 377 =
- 10.Leapfrog list (each number is the sum of the two before it): 5, 4, 9, 13, 22, 35, 57, 92, 149, 241. What is 11 × the 7th number?
- 11.4 + 3 + 7 + 10 + 17 + 27 + 44 + 71 + 115 + 186 =
- 12.7 + 5 + 12 + 17 + 29 + 46 + 75 + 121 + 196 + 317 =
- 13.Leapfrog list (each number is the sum of the two before it): 4, 2, 6, 8, 14, 22, 36, 58, 94, 152. What is 11 × the 7th number?
- 14.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?
- 15.3 + 7 + 10 + 17 + 27 + 44 + 71 + 115 + 186 + 301 =
- 16.1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 =
- 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.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?
- 19.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?
- 20.A leapfrog list starts 3, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 21.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?
- 22.8 + 3 + 11 + 14 + 25 + 39 + 64 + 103 + 167 + 270 =
- 23.4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 + 356 =
- 24.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?
- 25.Leapfrog list (each number is the sum of the two before it): 6, 3, 9, 12, 21, 33, 54, 87, 141, 228. What is 11 × the 7th number?
- 26.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?
- 27.8 + 1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 =
- 28.A leapfrog list starts 6, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 29.Leapfrog list (each number is the sum of the two before it): 9, 3, 12, 15, 27, 42, 69, 111, 180, 291. What is 11 × the 7th number?
- 30.6 + 5 + 11 + 16 + 27 + 43 + 70 + 113 + 183 + 296 =
- 31.9 + 5 + 14 + 19 + 33 + 52 + 85 + 137 + 222 + 359 =
- 32.3 + 2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 =
- 33.A leapfrog list starts 3, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 34.Leapfrog list (each number is the sum of the two before it): 6, 5, 11, 16, 27, 43, 70, 113, 183, 296. What is 11 × the 7th number?
- 35.9 + 9 + 18 + 27 + 45 + 72 + 117 + 189 + 306 + 495 =
- 36.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?
- 37.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?
- 38.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?
- 39.4 + 2 + 6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 =
- 40.Leapfrog list (each number is the sum of the two before it): 3, 2, 5, 7, 12, 19, 31, 50, 81, 131. What is 11 × the 7th number?
Answer key
- 561
- 495
- 429
- 495
- 1056
- 484
- 671
- 506
- 979
- 627
- 484
- 825
- 396
- 880
- 781
- 407
- 407
- 286
- 726
- 517
- 473
- 704
- 924
- 759
- 594
- 638
- 528
- 1122
- 759
- 770
- 935
- 341
- 605
- 770
- 1287
- 253
- 528
- 561
- 396
- 341
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