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
- 1.1 + 6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 + 225 =
- 2.5 + 2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 =
- 3.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?
- 4.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?
- 5.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?
- 6.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?
- 7.6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 + 267 + 432 =
- 8.Leapfrog list (each number is the sum of the two before it): 7, 5, 12, 17, 29, 46, 75, 121, 196, 317. What is 11 × the 7th number?
- 9.1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 + 327 =
- 10.7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 + 453 =
- 11.3 + 3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 =
- 12.A leapfrog list starts 5, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 13.9 + 3 + 12 + 15 + 27 + 42 + 69 + 111 + 180 + 291 =
- 14.5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 + 254 + 411 =
- 15.A leapfrog list starts 9, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 16.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?
- 17.Leapfrog list (each number is the sum of the two before it): 2, 1, 3, 4, 7, 11, 18, 29, 47, 76. What is 11 × the 7th number?
- 18.6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 + 398 =
- 19.7 + 3 + 10 + 13 + 23 + 36 + 59 + 95 + 154 + 249 =
- 20.A leapfrog list starts 2, 3 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): 5, 6, 11, 17, 28, 45, 73, 118, 191, 309. What is 11 × the 7th number?
- 22.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?
- 23.Leapfrog list (each number is the sum of the two before it): 7, 7, 14, 21, 35, 56, 91, 147, 238, 385. What is 11 × the 7th number?
- 24.6 + 5 + 11 + 16 + 27 + 43 + 70 + 113 + 183 + 296 =
- 25.2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 + 314 =
- 26.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?
- 27.4 + 2 + 6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 =
- 28.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?
- 29.8 + 4 + 12 + 16 + 28 + 44 + 72 + 116 + 188 + 304 =
- 30.2 + 2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 =
- 31.A leapfrog list starts 5, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 32.9 + 6 + 15 + 21 + 36 + 57 + 93 + 150 + 243 + 393 =
- 33.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?
- 34.A leapfrog list starts 4, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 35.2 + 1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 =
- 36.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?
- 37.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?
- 38.4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 + 199 + 322 =
- 39.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?
- 40.1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 =
Answer key
- 583
- 451
- 627
- 605
- 429
- 451
- 1122
- 825
- 847
- 1177
- 429
- 539
- 759
- 1067
- 1287
- 979
- 198
- 1034
- 649
- 374
- 803
- 1177
- 1001
- 770
- 814
- 319
- 396
- 550
- 792
- 286
- 979
- 1023
- 319
- 748
- 198
- 572
- 1012
- 836
- 715
- 495
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