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): 9, 1, 10, 11, 21, 32, 53, 85, 138, 223. What is 11 × the 7th number?
- 2.4 + 2 + 6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 =
- 3.3 + 3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 =
- 4.A leapfrog list starts 5, 8 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 9, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 6.1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 =
- 7.2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 =
- 8.8 + 1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 =
- 9.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?
- 10.A leapfrog list starts 5, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 11.1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 + 259 =
- 12.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?
- 13.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?
- 14.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?
- 15.2 + 6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 =
- 16.A leapfrog list starts 1, 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 2, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 18.8 + 6 + 14 + 20 + 34 + 54 + 88 + 142 + 230 + 372 =
- 19.6 + 6 + 12 + 18 + 30 + 48 + 78 + 126 + 204 + 330 =
- 20.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?
- 21.8 + 5 + 13 + 18 + 31 + 49 + 80 + 129 + 209 + 338 =
- 22.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?
- 23.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?
- 24.4 + 3 + 7 + 10 + 17 + 27 + 44 + 71 + 115 + 186 =
- 25.Leapfrog list (each number is the sum of the two before it): 4, 3, 7, 10, 17, 27, 44, 71, 115, 186. What is 11 × the 7th number?
- 26.A leapfrog list starts 4, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 27.2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 + 314 =
- 28.A leapfrog list starts 4, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 29.A leapfrog list starts 1, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 30.6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 + 398 =
- 31.4 + 1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 =
- 32.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?
- 33.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?
- 34.7 + 6 + 13 + 19 + 32 + 51 + 83 + 134 + 217 + 351 =
- 35.A leapfrog list starts 8, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 36.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?
- 37.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?
- 38.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?
- 39.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?
- 40.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?
Answer key
- 583
- 396
- 429
- 979
- 671
- 407
- 550
- 528
- 1111
- 627
- 671
- 935
- 462
- 781
- 638
- 847
- 550
- 968
- 858
- 1111
- 880
- 968
- 319
- 484
- 484
- 924
- 814
- 308
- 143
- 1034
- 308
- 946
- 396
- 913
- 616
- 671
- 913
- 143
- 605
- 869
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