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
- 1.4 + 4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 =
- 2.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?
- 3.Leapfrog list (each number is the sum of the two before it): 2, 8, 10, 18, 28, 46, 74, 120, 194, 314. What is 11 × the 7th number?
- 4.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?
- 5.8 + 4 + 12 + 16 + 28 + 44 + 72 + 116 + 188 + 304 =
- 6.1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 =
- 7.4 + 9 + 13 + 22 + 35 + 57 + 92 + 149 + 241 + 390 =
- 8.6 + 3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 =
- 9.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?
- 10.9 + 3 + 12 + 15 + 27 + 42 + 69 + 111 + 180 + 291 =
- 11.Leapfrog list (each number is the sum of the two before it): 3, 1, 4, 5, 9, 14, 23, 37, 60, 97. What is 11 × the 7th number?
- 12.A leapfrog list starts 9, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 13.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?
- 14.1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 =
- 15.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?
- 16.8 + 1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 =
- 17.9 + 8 + 17 + 25 + 42 + 67 + 109 + 176 + 285 + 461 =
- 18.A leapfrog list starts 4, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 19.7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 + 259 + 419 =
- 20.Leapfrog list (each number is the sum of the two before it): 3, 3, 6, 9, 15, 24, 39, 63, 102, 165. What is 11 × the 7th number?
- 21.Leapfrog list (each number is the sum of the two before it): 9, 6, 15, 21, 36, 57, 93, 150, 243, 393. What is 11 × the 7th number?
- 22.7 + 5 + 12 + 17 + 29 + 46 + 75 + 121 + 196 + 317 =
- 23.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?
- 24.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?
- 25.A leapfrog list starts 4, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 26.6 + 4 + 10 + 14 + 24 + 38 + 62 + 100 + 162 + 262 =
- 27.Leapfrog list (each number is the sum of the two before it): 6, 8, 14, 22, 36, 58, 94, 152, 246, 398. What is 11 × the 7th number?
- 28.A leapfrog list starts 1, 7 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): 2, 7, 9, 16, 25, 41, 66, 107, 173, 280. What is 11 × the 7th number?
- 30.A leapfrog list starts 9, 3 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): 5, 7, 12, 19, 31, 50, 81, 131, 212, 343. What is 11 × the 7th number?
- 32.A leapfrog list starts 9, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 33.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?
- 34.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?
- 35.2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 =
- 36.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?
- 37.A leapfrog list starts 3, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 38.2 + 1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 =
- 39.1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 + 327 =
- 40.7 + 2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 =
Answer key
- 572
- 781
- 814
- 539
- 792
- 319
- 1012
- 594
- 550
- 759
- 253
- 1111
- 341
- 231
- 759
- 528
- 1199
- 748
- 1089
- 429
- 1023
- 825
- 605
- 891
- 572
- 682
- 1034
- 671
- 726
- 759
- 891
- 583
- 649
- 748
- 550
- 396
- 429
- 198
- 847
- 561
Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks