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, 5, 10, 15, 25, 40, 65, 105, 170, 275. What is 11 × the 7th number?
- 2.1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 + 327 =
- 3.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?
- 4.Leapfrog list (each number is the sum of the two before it): 8, 6, 14, 20, 34, 54, 88, 142, 230, 372. What is 11 × the 7th number?
- 5.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?
- 6.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?
- 7.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?
- 8.6 + 6 + 12 + 18 + 30 + 48 + 78 + 126 + 204 + 330 =
- 9.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?
- 10.Leapfrog list (each number is the sum of the two before it): 7, 8, 15, 23, 38, 61, 99, 160, 259, 419. What is 11 × the 7th number?
- 11.4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 + 356 =
- 12.Leapfrog list (each number is the sum of the two before it): 9, 2, 11, 13, 24, 37, 61, 98, 159, 257. What is 11 × the 7th number?
- 13.8 + 4 + 12 + 16 + 28 + 44 + 72 + 116 + 188 + 304 =
- 14.3 + 1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 =
- 15.A leapfrog list starts 3, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 16.6 + 5 + 11 + 16 + 27 + 43 + 70 + 113 + 183 + 296 =
- 17.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?
- 18.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?
- 19.3 + 3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 =
- 20.4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 + 178 + 288 =
- 21.A leapfrog list starts 4, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 22.A leapfrog list starts 8, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 23.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?
- 24.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?
- 25.Leapfrog list (each number is the sum of the two before it): 4, 7, 11, 18, 29, 47, 76, 123, 199, 322. What is 11 × the 7th number?
- 26.7 + 1 + 8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 =
- 27.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?
- 28.3 + 8 + 11 + 19 + 30 + 49 + 79 + 128 + 207 + 335 =
- 29.4 + 1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 =
- 30.Leapfrog list (each number is the sum of the two before it): 3, 4, 7, 11, 18, 29, 47, 76, 123, 199. What is 11 × the 7th number?
- 31.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?
- 32.Leapfrog list (each number is the sum of the two before it): 9, 5, 14, 19, 33, 52, 85, 137, 222, 359. What is 11 × the 7th number?
- 33.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?
- 34.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?
- 35.7 + 6 + 13 + 19 + 32 + 51 + 83 + 134 + 217 + 351 =
- 36.1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 =
- 37.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?
- 38.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?
- 39.7 + 7 + 14 + 21 + 35 + 56 + 91 + 147 + 238 + 385 =
- 40.A leapfrog list starts 8, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
Answer key
- 715
- 847
- 858
- 968
- 231
- 396
- 561
- 858
- 451
- 1089
- 924
- 671
- 792
- 253
- 781
- 770
- 1056
- 671
- 429
- 748
- 1012
- 704
- 759
- 253
- 836
- 473
- 946
- 869
- 308
- 517
- 946
- 935
- 1001
- 693
- 913
- 495
- 429
- 198
- 1001
- 1232
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