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, 1, 6, 7, 13, 20, 33, 53, 86, 139. What is 11 × the 7th number?
- 2.4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 + 178 + 288 =
- 3.Leapfrog list (each number is the sum of the two before it): 1, 5, 6, 11, 17, 28, 45, 73, 118, 191. What is 11 × the 7th number?
- 4.A leapfrog list starts 9, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 5.3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 + 233 =
- 6.A leapfrog list starts 7, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 7.2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 + 348 =
- 8.A leapfrog list starts 9, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 9.A leapfrog list starts 8, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 10.4 + 1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 =
- 11.7 + 7 + 14 + 21 + 35 + 56 + 91 + 147 + 238 + 385 =
- 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?
- 13.3 + 3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 =
- 14.1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 =
- 15.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?
- 16.Leapfrog list (each number is the sum of the two before it): 2, 4, 6, 10, 16, 26, 42, 68, 110, 178. What is 11 × the 7th number?
- 17.8 + 1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 =
- 18.2 + 6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 =
- 19.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?
- 20.5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 + 309 =
- 21.Leapfrog list (each number is the sum of the two before it): 8, 1, 9, 10, 19, 29, 48, 77, 125, 202. What is 11 × the 7th number?
- 22.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?
- 23.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?
- 24.Leapfrog list (each number is the sum of the two before it): 3, 5, 8, 13, 21, 34, 55, 89, 144, 233. What is 11 × the 7th number?
- 25.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?
- 26.Leapfrog list (each number is the sum of the two before it): 2, 5, 7, 12, 19, 31, 50, 81, 131, 212. What is 11 × the 7th number?
- 27.A leapfrog list starts 1, 8 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 2, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 29.4 + 9 + 13 + 22 + 35 + 57 + 92 + 149 + 241 + 390 =
- 30.Leapfrog list (each number is the sum of the two before it): 9, 7, 16, 23, 39, 62, 101, 163, 264, 427. What is 11 × the 7th number?
- 31.Leapfrog list (each number is the sum of the two before it): 7, 4, 11, 15, 26, 41, 67, 108, 175, 283. What is 11 × the 7th number?
- 32.A leapfrog list starts 3, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 33.Leapfrog list (each number is the sum of the two before it): 9, 6, 15, 21, 36, 57, 93, 150, 243, 393. What is 11 × the 7th number?
- 34.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?
- 35.7 + 6 + 13 + 19 + 32 + 51 + 83 + 134 + 217 + 351 =
- 36.2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 =
- 37.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?
- 38.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?
- 39.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?
- 40.8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 + 474 =
Answer key
- 363
- 748
- 495
- 1111
- 605
- 1177
- 902
- 759
- 528
- 308
- 1001
- 671
- 429
- 319
- 1089
- 462
- 528
- 638
- 869
- 803
- 528
- 715
- 1232
- 605
- 143
- 550
- 759
- 638
- 1012
- 1111
- 737
- 253
- 1023
- 847
- 913
- 726
- 561
- 649
- 1199
- 1232
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