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
- 1.3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 + 199 =
- 2.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?
- 3.A leapfrog list starts 7, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 4.4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 + 254 =
- 5.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?
- 6.8 + 4 + 12 + 16 + 28 + 44 + 72 + 116 + 188 + 304 =
- 7.7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 + 259 + 419 =
- 8.7 + 1 + 8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 =
- 9.5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 + 343 =
- 10.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?
- 11.8 + 6 + 14 + 20 + 34 + 54 + 88 + 142 + 230 + 372 =
- 12.Leapfrog list (each number is the sum of the two before it): 5, 4, 9, 13, 22, 35, 57, 92, 149, 241. What is 11 × the 7th number?
- 13.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?
- 14.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?
- 15.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?
- 16.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?
- 17.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?
- 18.A leapfrog list starts 1, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 19.3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 + 233 =
- 20.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?
- 21.A leapfrog list starts 5, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 22.Leapfrog list (each number is the sum of the two before it): 9, 3, 12, 15, 27, 42, 69, 111, 180, 291. What is 11 × the 7th number?
- 23.9 + 9 + 18 + 27 + 45 + 72 + 117 + 189 + 306 + 495 =
- 24.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?
- 25.2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 =
- 26.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?
- 27.1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 + 327 =
- 28.Leapfrog list (each number is the sum of the two before it): 6, 9, 15, 24, 39, 63, 102, 165, 267, 432. What is 11 × the 7th number?
- 29.4 + 1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 =
- 30.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?
- 31.Leapfrog list (each number is the sum of the two before it): 8, 6, 14, 20, 34, 54, 88, 142, 230, 372. What is 11 × the 7th number?
- 32.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?
- 33.2 + 2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 =
- 34.A leapfrog list starts 6, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 35.A leapfrog list starts 1, 4 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 7, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 37.7 + 3 + 10 + 13 + 23 + 36 + 59 + 95 + 154 + 249 =
- 38.5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 + 254 + 411 =
- 39.4 + 3 + 7 + 10 + 17 + 27 + 44 + 71 + 115 + 186 =
- 40.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?
Answer key
- 517
- 286
- 1001
- 660
- 550
- 792
- 1089
- 473
- 891
- 638
- 968
- 627
- 583
- 341
- 1089
- 1111
- 1056
- 231
- 605
- 605
- 539
- 759
- 1287
- 891
- 550
- 484
- 847
- 1122
- 308
- 143
- 968
- 1056
- 286
- 594
- 407
- 737
- 649
- 1067
- 484
- 693
Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks