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
- 1.8 + 6 + 14 + 20 + 34 + 54 + 88 + 142 + 230 + 372 =
- 2.5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 + 343 =
- 3.Leapfrog list (each number is the sum of the two before it): 3, 7, 10, 17, 27, 44, 71, 115, 186, 301. What is 11 × the 7th number?
- 4.2 + 6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 =
- 5.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?
- 6.4 + 1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 =
- 7.4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 + 199 + 322 =
- 8.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?
- 9.7 + 4 + 11 + 15 + 26 + 41 + 67 + 108 + 175 + 283 =
- 10.2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 =
- 11.3 + 3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 =
- 12.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?
- 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 7, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 15.9 + 2 + 11 + 13 + 24 + 37 + 61 + 98 + 159 + 257 =
- 16.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?
- 17.8 + 2 + 10 + 12 + 22 + 34 + 56 + 90 + 146 + 236 =
- 18.Leapfrog list (each number is the sum of the two before it): 2, 1, 3, 4, 7, 11, 18, 29, 47, 76. What is 11 × the 7th number?
- 19.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?
- 20.1 + 6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 + 225 =
- 21.5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 + 254 + 411 =
- 22.4 + 9 + 13 + 22 + 35 + 57 + 92 + 149 + 241 + 390 =
- 23.5 + 2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 =
- 24.A leapfrog list starts 4, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 25.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?
- 26.3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 + 267 =
- 27.Leapfrog list (each number is the sum of the two before it): 2, 2, 4, 6, 10, 16, 26, 42, 68, 110. What is 11 × the 7th number?
- 28.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?
- 29.Leapfrog list (each number is the sum of the two before it): 1, 2, 3, 5, 8, 13, 21, 34, 55, 89. What is 11 × the 7th number?
- 30.A leapfrog list starts 8, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 31.Leapfrog list (each number is the sum of the two before it): 3, 5, 8, 13, 21, 34, 55, 89, 144, 233. What is 11 × the 7th number?
- 32.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?
- 33.Leapfrog list (each number is the sum of the two before it): 7, 1, 8, 9, 17, 26, 43, 69, 112, 181. What is 11 × the 7th number?
- 34.Leapfrog list (each number is the sum of the two before it): 4, 8, 12, 20, 32, 52, 84, 136, 220, 356. What is 11 × the 7th number?
- 35.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?
- 36.2 + 2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 =
- 37.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?
- 38.1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 + 327 =
- 39.A leapfrog list starts 3, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 40.Leapfrog list (each number is the sum of the two before it): 9, 9, 18, 27, 45, 72, 117, 189, 306, 495. What is 11 × the 7th number?
Answer key
- 968
- 891
- 781
- 638
- 891
- 308
- 836
- 583
- 737
- 374
- 429
- 671
- 1056
- 649
- 671
- 561
- 616
- 198
- 880
- 583
- 1067
- 1012
- 451
- 924
- 517
- 693
- 286
- 1089
- 231
- 528
- 605
- 759
- 473
- 924
- 726
- 286
- 759
- 847
- 341
- 1287
Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks