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 + 6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 + 225 =
- 2.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?
- 3.9 + 9 + 18 + 27 + 45 + 72 + 117 + 189 + 306 + 495 =
- 4.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?
- 5.Leapfrog list (each number is the sum of the two before it): 6, 4, 10, 14, 24, 38, 62, 100, 162, 262. What is 11 × the 7th number?
- 6.2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 =
- 7.5 + 1 + 6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 =
- 8.Leapfrog list (each number is the sum of the two before it): 6, 8, 14, 22, 36, 58, 94, 152, 246, 398. What is 11 × the 7th number?
- 9.2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 + 348 =
- 10.A leapfrog list starts 7, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 11.3 + 3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 =
- 12.3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 + 267 =
- 13.7 + 6 + 13 + 19 + 32 + 51 + 83 + 134 + 217 + 351 =
- 14.Leapfrog list (each number is the sum of the two before it): 1, 8, 9, 17, 26, 43, 69, 112, 181, 293. What is 11 × the 7th number?
- 15.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?
- 16.1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 =
- 17.Leapfrog list (each number is the sum of the two before it): 5, 8, 13, 21, 34, 55, 89, 144, 233, 377. What is 11 × the 7th number?
- 18.A leapfrog list starts 8, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 19.A leapfrog list starts 7, 2 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): 2, 6, 8, 14, 22, 36, 58, 94, 152, 246. What is 11 × the 7th number?
- 21.2 + 1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 =
- 22.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?
- 23.8 + 3 + 11 + 14 + 25 + 39 + 64 + 103 + 167 + 270 =
- 24.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?
- 25.2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 =
- 26.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?
- 27.9 + 7 + 16 + 23 + 39 + 62 + 101 + 163 + 264 + 427 =
- 28.A leapfrog list starts 1, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 29.1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 =
- 30.1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 + 259 =
- 31.2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 + 314 =
- 32.Leapfrog list (each number is the sum of the two before it): 8, 8, 16, 24, 40, 64, 104, 168, 272, 440. What is 11 × the 7th number?
- 33.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?
- 34.A leapfrog list starts 2, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 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.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?
- 37.A leapfrog list starts 7, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 38.3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 + 233 =
- 39.Leapfrog list (each number is the sum of the two before it): 2, 3, 5, 8, 13, 21, 34, 55, 89, 144. What is 11 × the 7th number?
- 40.3 + 2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 =
Answer key
- 583
- 363
- 1287
- 880
- 682
- 374
- 363
- 1034
- 902
- 1001
- 429
- 693
- 913
- 759
- 1177
- 231
- 979
- 1144
- 561
- 638
- 198
- 671
- 704
- 495
- 726
- 616
- 1111
- 583
- 495
- 671
- 814
- 1144
- 506
- 198
- 517
- 869
- 1089
- 605
- 374
- 341
Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks