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, 9, 17, 26, 43, 69, 112, 181, 293, 474. What is 11 × the 7th number?
- 2.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?
- 3.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?
- 4.A leapfrog list starts 2, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 5.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?
- 6.6 + 3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 =
- 7.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?
- 8.3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 + 199 =
- 9.A leapfrog list starts 7, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 10.A leapfrog list starts 9, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 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): 1, 1, 2, 3, 5, 8, 13, 21, 34, 55. What is 11 × the 7th number?
- 13.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?
- 14.A leapfrog list starts 6, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 15.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?
- 16.Leapfrog list (each number is the sum of the two before it): 5, 2, 7, 9, 16, 25, 41, 66, 107, 173. What is 11 × the 7th number?
- 17.4 + 2 + 6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 =
- 18.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?
- 19.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?
- 20.6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 + 267 + 432 =
- 21.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?
- 22.Leapfrog list (each number is the sum of the two before it): 8, 5, 13, 18, 31, 49, 80, 129, 209, 338. What is 11 × the 7th number?
- 23.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?
- 24.9 + 9 + 18 + 27 + 45 + 72 + 117 + 189 + 306 + 495 =
- 25.4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 + 356 =
- 26.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?
- 27.A leapfrog list starts 9, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 28.6 + 1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 =
- 29.9 + 1 + 10 + 11 + 21 + 32 + 53 + 85 + 138 + 223 =
- 30.A leapfrog list starts 5, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 31.A leapfrog list starts 7, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 32.3 + 8 + 11 + 19 + 30 + 49 + 79 + 128 + 207 + 335 =
- 33.4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 + 254 =
- 34.3 + 3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 =
- 35.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?
- 36.9 + 8 + 17 + 25 + 42 + 67 + 109 + 176 + 285 + 461 =
- 37.6 + 4 + 10 + 14 + 24 + 38 + 62 + 100 + 162 + 262 =
- 38.Leapfrog list (each number is the sum of the two before it): 4, 9, 13, 22, 35, 57, 92, 149, 241, 390. What is 11 × the 7th number?
- 39.2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 =
- 40.2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 + 314 =
Answer key
- 1232
- 341
- 1056
- 726
- 803
- 594
- 1199
- 517
- 649
- 671
- 341
- 143
- 1001
- 418
- 1056
- 451
- 396
- 561
- 495
- 1122
- 1023
- 880
- 649
- 1287
- 924
- 517
- 935
- 418
- 583
- 363
- 473
- 869
- 660
- 429
- 517
- 1199
- 682
- 1012
- 550
- 814
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