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): 9, 8, 17, 25, 42, 67, 109, 176, 285, 461. What is 11 × the 7th number?
- 2.Leapfrog list (each number is the sum of the two before it): 3, 3, 6, 9, 15, 24, 39, 63, 102, 165. What is 11 × the 7th number?
- 3.6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 + 267 + 432 =
- 4.1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 =
- 5.A leapfrog list starts 6, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 6.5 + 3 + 8 + 11 + 19 + 30 + 49 + 79 + 128 + 207 =
- 7.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?
- 8.1 + 6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 + 225 =
- 9.1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 =
- 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?
- 11.9 + 7 + 16 + 23 + 39 + 62 + 101 + 163 + 264 + 427 =
- 12.A leapfrog list starts 1, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 13.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?
- 14.A leapfrog list starts 1, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 15.3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 + 233 =
- 16.2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 =
- 17.8 + 8 + 16 + 24 + 40 + 64 + 104 + 168 + 272 + 440 =
- 18.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?
- 19.Leapfrog list (each number is the sum of the two before it): 9, 1, 10, 11, 21, 32, 53, 85, 138, 223. What is 11 × the 7th number?
- 20.3 + 1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 =
- 21.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?
- 22.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?
- 23.5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 + 309 =
- 24.A leapfrog list starts 8, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 25.2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 + 348 =
- 26.6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 + 398 =
- 27.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?
- 28.A leapfrog list starts 4, 4 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 3, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 30.6 + 4 + 10 + 14 + 24 + 38 + 62 + 100 + 162 + 262 =
- 31.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?
- 32.A leapfrog list starts 9, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 33.7 + 5 + 12 + 17 + 29 + 46 + 75 + 121 + 196 + 317 =
- 34.A leapfrog list starts 7, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 35.A leapfrog list starts 6, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 36.3 + 8 + 11 + 19 + 30 + 49 + 79 + 128 + 207 + 335 =
- 37.Leapfrog list (each number is the sum of the two before it): 4, 6, 10, 16, 26, 42, 68, 110, 178, 288. What is 11 × the 7th number?
- 38.2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 + 314 =
- 39.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?
- 40.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?
Answer key
- 1199
- 429
- 1122
- 319
- 1034
- 539
- 583
- 583
- 495
- 803
- 1111
- 583
- 759
- 495
- 605
- 374
- 1144
- 451
- 583
- 253
- 286
- 1056
- 803
- 1056
- 902
- 1034
- 341
- 572
- 517
- 682
- 1034
- 847
- 825
- 913
- 946
- 869
- 748
- 814
- 847
- 319
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