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 + 8 + 13 + 21 + 34 + 55 + 89 + 144 + 233 + 377 =
- 2.9 + 9 + 18 + 27 + 45 + 72 + 117 + 189 + 306 + 495 =
- 3.Leapfrog list (each number is the sum of the two before it): 2, 9, 11, 20, 31, 51, 82, 133, 215, 348. What is 11 × the 7th number?
- 4.8 + 4 + 12 + 16 + 28 + 44 + 72 + 116 + 188 + 304 =
- 5.7 + 6 + 13 + 19 + 32 + 51 + 83 + 134 + 217 + 351 =
- 6.Leapfrog list (each number is the sum of the two before it): 5, 7, 12, 19, 31, 50, 81, 131, 212, 343. What is 11 × the 7th number?
- 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.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?
- 9.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?
- 10.A leapfrog list starts 5, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 11.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?
- 12.1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 =
- 13.A leapfrog list starts 3, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 14.6 + 5 + 11 + 16 + 27 + 43 + 70 + 113 + 183 + 296 =
- 15.6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 + 225 + 364 =
- 16.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?
- 17.A leapfrog list starts 5, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 18.Leapfrog list (each number is the sum of the two before it): 4, 1, 5, 6, 11, 17, 28, 45, 73, 118. What is 11 × the 7th number?
- 19.Leapfrog list (each number is the sum of the two before it): 9, 1, 10, 11, 21, 32, 53, 85, 138, 223. What is 11 × the 7th number?
- 20.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?
- 21.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?
- 22.2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 =
- 23.6 + 1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 =
- 24.3 + 2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 =
- 25.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?
- 26.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?
- 27.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?
- 28.A leapfrog list starts 3, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 29.2 + 6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 =
- 30.Leapfrog list (each number is the sum of the two before it): 9, 7, 16, 23, 39, 62, 101, 163, 264, 427. What is 11 × the 7th number?
- 31.9 + 2 + 11 + 13 + 24 + 37 + 61 + 98 + 159 + 257 =
- 32.A leapfrog list starts 2, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 33.3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 + 267 =
- 34.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?
- 35.Leapfrog list (each number is the sum of the two before it): 3, 6, 9, 15, 24, 39, 63, 102, 165, 267. What is 11 × the 7th number?
- 36.Leapfrog list (each number is the sum of the two before it): 9, 4, 13, 17, 30, 47, 77, 124, 201, 325. What is 11 × the 7th number?
- 37.A leapfrog list starts 6, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 38.A leapfrog list starts 1, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 39.1 + 8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 =
- 40.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?
Answer key
- 979
- 1287
- 902
- 792
- 913
- 891
- 1287
- 759
- 1122
- 891
- 638
- 319
- 605
- 770
- 946
- 143
- 451
- 308
- 583
- 506
- 1056
- 374
- 418
- 341
- 748
- 770
- 1177
- 693
- 638
- 1111
- 671
- 550
- 693
- 649
- 693
- 847
- 418
- 143
- 759
- 704
Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks