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
- 1.5 + 5 + 10 + 15 + 25 + 40 + 65 + 105 + 170 + 275 =
- 2.Leapfrog list (each number is the sum of the two before it): 8, 9, 17, 26, 43, 69, 112, 181, 293, 474. What is 11 × the 7th number?
- 3.A leapfrog list starts 2, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 4.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?
- 5.7 + 7 + 14 + 21 + 35 + 56 + 91 + 147 + 238 + 385 =
- 6.7 + 6 + 13 + 19 + 32 + 51 + 83 + 134 + 217 + 351 =
- 7.Leapfrog list (each number is the sum of the two before it): 7, 8, 15, 23, 38, 61, 99, 160, 259, 419. What is 11 × the 7th number?
- 8.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?
- 9.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?
- 10.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?
- 11.6 + 1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 =
- 12.3 + 3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 =
- 13.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?
- 14.3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 + 233 =
- 15.5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 + 233 + 377 =
- 16.A leapfrog list starts 2, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 17.Leapfrog list (each number is the sum of the two before it): 8, 3, 11, 14, 25, 39, 64, 103, 167, 270. What is 11 × the 7th number?
- 18.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?
- 19.4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 + 178 + 288 =
- 20.2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 + 314 =
- 21.8 + 8 + 16 + 24 + 40 + 64 + 104 + 168 + 272 + 440 =
- 22.1 + 6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 + 225 =
- 23.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?
- 24.4 + 1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 =
- 25.A leapfrog list starts 2, 7 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 6, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 27.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?
- 28.9 + 3 + 12 + 15 + 27 + 42 + 69 + 111 + 180 + 291 =
- 29.7 + 2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 =
- 30.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?
- 31.A leapfrog list starts 8, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 32.7 + 5 + 12 + 17 + 29 + 46 + 75 + 121 + 196 + 317 =
- 33.8 + 5 + 13 + 18 + 31 + 49 + 80 + 129 + 209 + 338 =
- 34.3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 + 369 =
- 35.1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 + 259 =
- 36.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?
- 37.Leapfrog list (each number is the sum of the two before it): 4, 6, 10, 16, 26, 42, 68, 110, 178, 288. What is 11 × the 7th number?
- 38.8 + 6 + 14 + 20 + 34 + 54 + 88 + 142 + 230 + 372 =
- 39.Leapfrog list (each number is the sum of the two before it): 9, 2, 11, 13, 24, 37, 61, 98, 159, 257. What is 11 × the 7th number?
- 40.A leapfrog list starts 2, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
Answer key
- 715
- 1232
- 902
- 770
- 1001
- 913
- 1089
- 407
- 1056
- 979
- 418
- 429
- 319
- 605
- 979
- 638
- 704
- 484
- 748
- 814
- 1144
- 583
- 462
- 308
- 726
- 1122
- 374
- 759
- 561
- 506
- 880
- 825
- 880
- 957
- 671
- 880
- 748
- 968
- 671
- 286
Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks