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
- 1.1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 =
- 2.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?
- 3.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?
- 4.7 + 3 + 10 + 13 + 23 + 36 + 59 + 95 + 154 + 249 =
- 5.A leapfrog list starts 2, 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 3, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 7.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?
- 8.5 + 4 + 9 + 13 + 22 + 35 + 57 + 92 + 149 + 241 =
- 9.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?
- 10.A leapfrog list starts 1, 4 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): 5, 6, 11, 17, 28, 45, 73, 118, 191, 309. What is 11 × the 7th number?
- 12.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?
- 13.3 + 3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 =
- 14.Leapfrog list (each number is the sum of the two before it): 9, 3, 12, 15, 27, 42, 69, 111, 180, 291. What is 11 × the 7th number?
- 15.8 + 5 + 13 + 18 + 31 + 49 + 80 + 129 + 209 + 338 =
- 16.Leapfrog list (each number is the sum of the two before it): 7, 9, 16, 25, 41, 66, 107, 173, 280, 453. What is 11 × the 7th number?
- 17.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?
- 18.1 + 1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 =
- 19.A leapfrog list starts 4, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 20.7 + 4 + 11 + 15 + 26 + 41 + 67 + 108 + 175 + 283 =
- 21.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?
- 22.A leapfrog list starts 5, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 23.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?
- 24.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?
- 25.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?
- 26.2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 + 314 =
- 27.8 + 1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 =
- 28.4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 + 199 + 322 =
- 29.8 + 2 + 10 + 12 + 22 + 34 + 56 + 90 + 146 + 236 =
- 30.5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 + 254 + 411 =
- 31.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?
- 32.9 + 3 + 12 + 15 + 27 + 42 + 69 + 111 + 180 + 291 =
- 33.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?
- 34.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?
- 35.5 + 1 + 6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 =
- 36.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?
- 37.4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 + 356 =
- 38.Leapfrog list (each number is the sum of the two before it): 5, 3, 8, 11, 19, 30, 49, 79, 128, 207. What is 11 × the 7th number?
- 39.1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 =
- 40.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?
Answer key
- 231
- 770
- 550
- 649
- 814
- 781
- 759
- 627
- 506
- 407
- 803
- 781
- 429
- 759
- 880
- 1177
- 374
- 143
- 484
- 737
- 429
- 1067
- 715
- 968
- 528
- 814
- 528
- 836
- 616
- 1067
- 649
- 759
- 814
- 649
- 363
- 979
- 924
- 539
- 319
- 913
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