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 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 =
- 2.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?
- 3.A leapfrog list starts 4, 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 3, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 5.8 + 2 + 10 + 12 + 22 + 34 + 56 + 90 + 146 + 236 =
- 6.2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 + 314 =
- 7.A leapfrog list starts 9, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 8.Leapfrog list (each number is the sum of the two before it): 7, 4, 11, 15, 26, 41, 67, 108, 175, 283. What is 11 × the 7th number?
- 9.8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 + 474 =
- 10.8 + 8 + 16 + 24 + 40 + 64 + 104 + 168 + 272 + 440 =
- 11.9 + 5 + 14 + 19 + 33 + 52 + 85 + 137 + 222 + 359 =
- 12.Leapfrog list (each number is the sum of the two before it): 5, 9, 14, 23, 37, 60, 97, 157, 254, 411. What is 11 × the 7th number?
- 13.Leapfrog list (each number is the sum of the two before it): 8, 7, 15, 22, 37, 59, 96, 155, 251, 406. What is 11 × the 7th number?
- 14.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?
- 15.7 + 3 + 10 + 13 + 23 + 36 + 59 + 95 + 154 + 249 =
- 16.3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 + 199 =
- 17.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?
- 18.A leapfrog list starts 3, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 19.6 + 4 + 10 + 14 + 24 + 38 + 62 + 100 + 162 + 262 =
- 20.2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 =
- 21.3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 + 233 =
- 22.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?
- 23.Leapfrog list (each number is the sum of the two before it): 6, 1, 7, 8, 15, 23, 38, 61, 99, 160. What is 11 × the 7th number?
- 24.9 + 8 + 17 + 25 + 42 + 67 + 109 + 176 + 285 + 461 =
- 25.Leapfrog list (each number is the sum of the two before it): 4, 4, 8, 12, 20, 32, 52, 84, 136, 220. What is 11 × the 7th number?
- 26.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?
- 27.5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 + 309 =
- 28.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?
- 29.2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 + 348 =
- 30.3 + 1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 =
- 31.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?
- 32.Leapfrog list (each number is the sum of the two before it): 7, 2, 9, 11, 20, 31, 51, 82, 133, 215. What is 11 × the 7th number?
- 33.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?
- 34.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?
- 35.5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 + 343 =
- 36.A leapfrog list starts 9, 4 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 2, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 38.3 + 8 + 11 + 19 + 30 + 49 + 79 + 128 + 207 + 335 =
- 39.1 + 8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 =
- 40.7 + 1 + 8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 =
Answer key
- 319
- 462
- 1012
- 253
- 616
- 814
- 1287
- 737
- 1232
- 1144
- 935
- 1067
- 1056
- 319
- 649
- 517
- 550
- 957
- 682
- 726
- 605
- 319
- 418
- 1199
- 572
- 143
- 803
- 627
- 902
- 253
- 671
- 561
- 484
- 616
- 891
- 847
- 726
- 869
- 759
- 473
Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks