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.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?
- 2.A leapfrog list starts 7, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 3.Leapfrog list (each number is the sum of the two before it): 5, 8, 13, 21, 34, 55, 89, 144, 233, 377. What is 11 × the 7th number?
- 4.5 + 3 + 8 + 11 + 19 + 30 + 49 + 79 + 128 + 207 =
- 5.3 + 2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 =
- 6.A leapfrog list starts 3, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 7.A leapfrog list starts 6, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 8.6 + 1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 =
- 9.1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 =
- 10.5 + 5 + 10 + 15 + 25 + 40 + 65 + 105 + 170 + 275 =
- 11.4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 + 254 =
- 12.6 + 2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 =
- 13.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?
- 14.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?
- 15.A leapfrog list starts 9, 4 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, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 17.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?
- 18.2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 =
- 19.6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 + 398 =
- 20.Leapfrog list (each number is the sum of the two before it): 7, 3, 10, 13, 23, 36, 59, 95, 154, 249. What is 11 × the 7th number?
- 21.Leapfrog list (each number is the sum of the two before it): 1, 7, 8, 15, 23, 38, 61, 99, 160, 259. What is 11 × the 7th number?
- 22.Leapfrog list (each number is the sum of the two before it): 7, 4, 11, 15, 26, 41, 67, 108, 175, 283. What is 11 × the 7th number?
- 23.5 + 1 + 6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 =
- 24.A leapfrog list starts 1, 9 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): 2, 8, 10, 18, 28, 46, 74, 120, 194, 314. What is 11 × the 7th number?
- 26.Leapfrog list (each number is the sum of the two before it): 2, 3, 5, 8, 13, 21, 34, 55, 89, 144. What is 11 × the 7th number?
- 27.4 + 4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 =
- 28.3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 + 267 =
- 29.A leapfrog list starts 2, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 30.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?
- 31.9 + 3 + 12 + 15 + 27 + 42 + 69 + 111 + 180 + 291 =
- 32.1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 =
- 33.7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 + 453 =
- 34.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?
- 35.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?
- 36.Leapfrog list (each number is the sum of the two before it): 4, 2, 6, 8, 14, 22, 36, 58, 94, 152. What is 11 × the 7th number?
- 37.Leapfrog list (each number is the sum of the two before it): 6, 1, 7, 8, 15, 23, 38, 61, 99, 160. What is 11 × the 7th number?
- 38.6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 + 267 + 432 =
- 39.2 + 1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 =
- 40.9 + 4 + 13 + 17 + 30 + 47 + 77 + 124 + 201 + 325 =
Answer key
- 550
- 825
- 979
- 539
- 341
- 517
- 858
- 418
- 231
- 715
- 660
- 506
- 1122
- 583
- 847
- 616
- 902
- 726
- 1034
- 649
- 671
- 737
- 363
- 847
- 814
- 374
- 572
- 693
- 902
- 759
- 759
- 319
- 1177
- 418
- 880
- 396
- 418
- 1122
- 198
- 847
Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks