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): 6, 9, 15, 24, 39, 63, 102, 165, 267, 432. What is 11 × the 7th number?
- 2.A leapfrog list starts 2, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 3.Leapfrog list (each number is the sum of the two before it): 1, 4, 5, 9, 14, 23, 37, 60, 97, 157. What is 11 × the 7th number?
- 4.2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 =
- 5.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?
- 6.A leapfrog list starts 6, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 7.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?
- 8.8 + 2 + 10 + 12 + 22 + 34 + 56 + 90 + 146 + 236 =
- 9.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?
- 10.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?
- 11.A leapfrog list starts 1, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 12.3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 + 267 =
- 13.A leapfrog list starts 4, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 14.A leapfrog list starts 4, 7 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): 7, 6, 13, 19, 32, 51, 83, 134, 217, 351. What is 11 × the 7th number?
- 16.A leapfrog list starts 6, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 17.A leapfrog list starts 7, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 18.8 + 3 + 11 + 14 + 25 + 39 + 64 + 103 + 167 + 270 =
- 19.A leapfrog list starts 4, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 20.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?
- 21.2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 + 314 =
- 22.1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 =
- 23.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?
- 24.7 + 4 + 11 + 15 + 26 + 41 + 67 + 108 + 175 + 283 =
- 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?
- 26.9 + 7 + 16 + 23 + 39 + 62 + 101 + 163 + 264 + 427 =
- 27.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?
- 28.A leapfrog list starts 3, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 29.5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 + 233 + 377 =
- 30.A leapfrog list starts 3, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 31.Leapfrog list (each number is the sum of the two before it): 6, 5, 11, 16, 27, 43, 70, 113, 183, 296. What is 11 × the 7th number?
- 32.Leapfrog list (each number is the sum of the two before it): 3, 7, 10, 17, 27, 44, 71, 115, 186, 301. What is 11 × the 7th number?
- 33.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?
- 34.1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 + 259 =
- 35.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?
- 36.7 + 5 + 12 + 17 + 29 + 46 + 75 + 121 + 196 + 317 =
- 37.2 + 6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 =
- 38.7 + 6 + 13 + 19 + 32 + 51 + 83 + 134 + 217 + 351 =
- 39.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?
- 40.4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 + 178 + 288 =
Answer key
- 1122
- 462
- 407
- 726
- 759
- 506
- 671
- 616
- 429
- 319
- 231
- 693
- 748
- 836
- 913
- 1122
- 737
- 704
- 660
- 451
- 814
- 495
- 803
- 737
- 836
- 1111
- 1001
- 429
- 979
- 869
- 770
- 781
- 935
- 671
- 1177
- 825
- 638
- 913
- 473
- 748
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