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): 7, 2, 9, 11, 20, 31, 51, 82, 133, 215. What is 11 × the 7th number?
- 3.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?
- 4.3 + 1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 =
- 5.1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 =
- 6.A leapfrog list starts 3, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 7.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?
- 8.4 + 2 + 6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 =
- 9.3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 + 199 =
- 10.2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 =
- 11.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?
- 12.Leapfrog list (each number is the sum of the two before it): 5, 7, 12, 19, 31, 50, 81, 131, 212, 343. What is 11 × the 7th number?
- 13.3 + 2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 =
- 14.Leapfrog list (each number is the sum of the two before it): 6, 8, 14, 22, 36, 58, 94, 152, 246, 398. What is 11 × the 7th number?
- 15.Leapfrog list (each number is the sum of the two before it): 6, 4, 10, 14, 24, 38, 62, 100, 162, 262. What is 11 × the 7th number?
- 16.8 + 3 + 11 + 14 + 25 + 39 + 64 + 103 + 167 + 270 =
- 17.Leapfrog list (each number is the sum of the two before it): 9, 9, 18, 27, 45, 72, 117, 189, 306, 495. What is 11 × the 7th number?
- 18.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?
- 19.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?
- 20.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?
- 21.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?
- 22.8 + 1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 =
- 23.3 + 8 + 11 + 19 + 30 + 49 + 79 + 128 + 207 + 335 =
- 24.Leapfrog list (each number is the sum of the two before it): 8, 8, 16, 24, 40, 64, 104, 168, 272, 440. What is 11 × the 7th number?
- 25.6 + 6 + 12 + 18 + 30 + 48 + 78 + 126 + 204 + 330 =
- 26.2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 + 314 =
- 27.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?
- 28.A leapfrog list starts 5, 6 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): 6, 7, 13, 20, 33, 53, 86, 139, 225, 364. What is 11 × the 7th number?
- 30.3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 + 267 =
- 31.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?
- 32.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?
- 33.1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 + 327 =
- 34.A leapfrog list starts 2, 1 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): 3, 8, 11, 19, 30, 49, 79, 128, 207, 335. What is 11 × the 7th number?
- 36.1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 =
- 37.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?
- 38.9 + 8 + 17 + 25 + 42 + 67 + 109 + 176 + 285 + 461 =
- 39.A leapfrog list starts 5, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 40.Leapfrog list (each number is the sum of the two before it): 2, 7, 9, 16, 25, 41, 66, 107, 173, 280. What is 11 × the 7th number?
Answer key
- 616
- 561
- 748
- 253
- 231
- 341
- 550
- 396
- 517
- 374
- 341
- 891
- 341
- 1034
- 682
- 704
- 1287
- 561
- 715
- 198
- 429
- 528
- 869
- 1144
- 858
- 814
- 253
- 803
- 946
- 693
- 286
- 649
- 847
- 198
- 869
- 319
- 803
- 1199
- 451
- 726
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