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
- 1.7 + 1 + 8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 =
- 2.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?
- 3.8 + 5 + 13 + 18 + 31 + 49 + 80 + 129 + 209 + 338 =
- 4.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?
- 5.9 + 4 + 13 + 17 + 30 + 47 + 77 + 124 + 201 + 325 =
- 6.2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 =
- 7.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?
- 8.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?
- 9.Leapfrog list (each number is the sum of the two before it): 3, 1, 4, 5, 9, 14, 23, 37, 60, 97. What is 11 × the 7th number?
- 10.6 + 2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 =
- 11.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?
- 12.5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 + 343 =
- 13.8 + 4 + 12 + 16 + 28 + 44 + 72 + 116 + 188 + 304 =
- 14.A leapfrog list starts 6, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 15.A leapfrog list starts 4, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 16.2 + 6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 =
- 17.4 + 2 + 6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 =
- 18.Leapfrog list (each number is the sum of the two before it): 6, 2, 8, 10, 18, 28, 46, 74, 120, 194. What is 11 × the 7th number?
- 19.1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 =
- 20.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?
- 21.9 + 2 + 11 + 13 + 24 + 37 + 61 + 98 + 159 + 257 =
- 22.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?
- 23.7 + 4 + 11 + 15 + 26 + 41 + 67 + 108 + 175 + 283 =
- 24.1 + 1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 =
- 25.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?
- 26.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?
- 27.4 + 9 + 13 + 22 + 35 + 57 + 92 + 149 + 241 + 390 =
- 28.7 + 7 + 14 + 21 + 35 + 56 + 91 + 147 + 238 + 385 =
- 29.1 + 8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 =
- 30.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?
- 31.Leapfrog list (each number is the sum of the two before it): 3, 9, 12, 21, 33, 54, 87, 141, 228, 369. What is 11 × the 7th number?
- 32.5 + 4 + 9 + 13 + 22 + 35 + 57 + 92 + 149 + 241 =
- 33.4 + 3 + 7 + 10 + 17 + 27 + 44 + 71 + 115 + 186 =
- 34.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?
- 35.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?
- 36.A leapfrog list starts 3, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 37.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?
- 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?
- 39.7 + 2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 =
- 40.1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 + 259 =
Answer key
- 473
- 913
- 880
- 561
- 847
- 726
- 429
- 539
- 253
- 506
- 484
- 891
- 792
- 770
- 572
- 638
- 396
- 506
- 319
- 517
- 671
- 517
- 737
- 143
- 319
- 748
- 1012
- 1001
- 759
- 396
- 957
- 627
- 484
- 638
- 759
- 253
- 1056
- 143
- 561
- 671
Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks