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 =
- 2.6 + 5 + 11 + 16 + 27 + 43 + 70 + 113 + 183 + 296 =
- 3.Leapfrog list (each number is the sum of the two before it): 4, 7, 11, 18, 29, 47, 76, 123, 199, 322. What is 11 × the 7th number?
- 4.4 + 1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 =
- 5.1 + 6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 + 225 =
- 6.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?
- 7.Leapfrog list (each number is the sum of the two before it): 5, 5, 10, 15, 25, 40, 65, 105, 170, 275. What is 11 × the 7th number?
- 8.7 + 1 + 8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 =
- 9.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?
- 10.3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 + 267 =
- 11.Leapfrog list (each number is the sum of the two before it): 5, 3, 8, 11, 19, 30, 49, 79, 128, 207. What is 11 × the 7th number?
- 12.5 + 1 + 6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 =
- 13.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?
- 14.9 + 3 + 12 + 15 + 27 + 42 + 69 + 111 + 180 + 291 =
- 15.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?
- 16.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?
- 17.A leapfrog list starts 8, 9 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): 3, 5, 8, 13, 21, 34, 55, 89, 144, 233. What is 11 × the 7th number?
- 19.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?
- 20.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?
- 21.8 + 5 + 13 + 18 + 31 + 49 + 80 + 129 + 209 + 338 =
- 22.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?
- 23.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?
- 24.5 + 2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 =
- 25.3 + 8 + 11 + 19 + 30 + 49 + 79 + 128 + 207 + 335 =
- 26.5 + 3 + 8 + 11 + 19 + 30 + 49 + 79 + 128 + 207 =
- 27.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?
- 28.A leapfrog list starts 5, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 29.3 + 2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 =
- 30.A leapfrog list starts 9, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 31.5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 + 309 =
- 32.A leapfrog list starts 8, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 33.8 + 4 + 12 + 16 + 28 + 44 + 72 + 116 + 188 + 304 =
- 34.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?
- 35.A leapfrog list starts 4, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 36.9 + 6 + 15 + 21 + 36 + 57 + 93 + 150 + 243 + 393 =
- 37.Leapfrog list (each number is the sum of the two before it): 4, 5, 9, 14, 23, 37, 60, 97, 157, 254. What is 11 × the 7th number?
- 38.5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 + 254 + 411 =
- 39.A leapfrog list starts 4, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 40.6 + 1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 =
Answer key
- 319
- 770
- 836
- 308
- 583
- 693
- 715
- 473
- 1232
- 693
- 539
- 363
- 484
- 759
- 341
- 880
- 1232
- 605
- 308
- 704
- 880
- 638
- 550
- 451
- 869
- 539
- 528
- 979
- 341
- 671
- 803
- 1144
- 792
- 781
- 308
- 1023
- 660
- 1067
- 396
- 418
Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks