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): 5, 8, 13, 21, 34, 55, 89, 144, 233, 377. What is 11 × the 7th number?
- 2.1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 + 327 =
- 3.6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 + 267 + 432 =
- 4.Leapfrog list (each number is the sum of the two before it): 9, 4, 13, 17, 30, 47, 77, 124, 201, 325. What is 11 × the 7th number?
- 5.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?
- 6.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?
- 7.7 + 3 + 10 + 13 + 23 + 36 + 59 + 95 + 154 + 249 =
- 8.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?
- 9.9 + 2 + 11 + 13 + 24 + 37 + 61 + 98 + 159 + 257 =
- 10.4 + 1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 =
- 11.8 + 7 + 15 + 22 + 37 + 59 + 96 + 155 + 251 + 406 =
- 12.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?
- 13.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?
- 14.Leapfrog list (each number is the sum of the two before it): 5, 1, 6, 7, 13, 20, 33, 53, 86, 139. What is 11 × the 7th number?
- 15.1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 =
- 16.A leapfrog list starts 3, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 17.4 + 4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 =
- 18.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?
- 19.8 + 5 + 13 + 18 + 31 + 49 + 80 + 129 + 209 + 338 =
- 20.A leapfrog list starts 5, 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): 6, 1, 7, 8, 15, 23, 38, 61, 99, 160. What is 11 × the 7th number?
- 22.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?
- 23.Leapfrog list (each number is the sum of the two before it): 1, 3, 4, 7, 11, 18, 29, 47, 76, 123. What is 11 × the 7th number?
- 24.4 + 3 + 7 + 10 + 17 + 27 + 44 + 71 + 115 + 186 =
- 25.7 + 1 + 8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 =
- 26.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?
- 27.Leapfrog list (each number is the sum of the two before it): 8, 9, 17, 26, 43, 69, 112, 181, 293, 474. What is 11 × the 7th number?
- 28.A leapfrog list starts 7, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 29.A leapfrog list starts 4, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 30.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?
- 31.3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 + 233 =
- 32.4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 + 356 =
- 33.8 + 1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 =
- 34.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?
- 35.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?
- 36.A leapfrog list starts 9, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 37.9 + 7 + 16 + 23 + 39 + 62 + 101 + 163 + 264 + 427 =
- 38.2 + 2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 =
- 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?
- 40.9 + 3 + 12 + 15 + 27 + 42 + 69 + 111 + 180 + 291 =
Answer key
- 979
- 847
- 1122
- 847
- 583
- 858
- 649
- 517
- 671
- 308
- 1056
- 1177
- 407
- 363
- 407
- 693
- 572
- 143
- 880
- 627
- 418
- 451
- 319
- 484
- 473
- 231
- 1232
- 825
- 660
- 803
- 605
- 924
- 528
- 792
- 495
- 583
- 1111
- 286
- 253
- 759
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