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, 9, 14, 23, 37, 60, 97, 157, 254, 411. What is 11 × the 7th number?
- 2.4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 + 356 =
- 3.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?
- 4.2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 =
- 5.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?
- 6.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?
- 7.2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 + 178 =
- 8.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?
- 9.5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 + 309 =
- 10.Leapfrog list (each number is the sum of the two before it): 6, 2, 8, 10, 18, 28, 46, 74, 120, 194. What is 11 × the 7th number?
- 11.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?
- 12.A leapfrog list starts 8, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 13.A leapfrog list starts 1, 7 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): 4, 2, 6, 8, 14, 22, 36, 58, 94, 152. What is 11 × the 7th number?
- 15.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?
- 16.9 + 3 + 12 + 15 + 27 + 42 + 69 + 111 + 180 + 291 =
- 17.Leapfrog list (each number is the sum of the two before it): 2, 9, 11, 20, 31, 51, 82, 133, 215, 348. What is 11 × the 7th number?
- 18.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?
- 19.1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 =
- 20.7 + 1 + 8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 =
- 21.4 + 4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 =
- 22.5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 + 233 + 377 =
- 23.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?
- 24.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?
- 25.A leapfrog list starts 2, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 26.Leapfrog list (each number is the sum of the two before it): 1, 9, 10, 19, 29, 48, 77, 125, 202, 327. What is 11 × the 7th number?
- 27.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?
- 28.1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 =
- 29.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?
- 30.7 + 2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 =
- 31.3 + 3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 =
- 32.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?
- 33.2 + 1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 =
- 34.2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 =
- 35.3 + 2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 =
- 36.8 + 3 + 11 + 14 + 25 + 39 + 64 + 103 + 167 + 270 =
- 37.6 + 5 + 11 + 16 + 27 + 43 + 70 + 113 + 183 + 296 =
- 38.3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 + 199 =
- 39.Leapfrog list (each number is the sum of the two before it): 2, 8, 10, 18, 28, 46, 74, 120, 194, 314. 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
- 1067
- 924
- 319
- 726
- 418
- 1012
- 462
- 1199
- 803
- 506
- 715
- 880
- 671
- 396
- 374
- 759
- 902
- 1287
- 495
- 473
- 572
- 979
- 1056
- 913
- 286
- 847
- 1089
- 407
- 143
- 561
- 429
- 1056
- 198
- 550
- 341
- 704
- 770
- 517
- 814
- 319
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