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 3, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 2.6 + 6 + 12 + 18 + 30 + 48 + 78 + 126 + 204 + 330 =
- 3.4 + 1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 =
- 4.2 + 1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 =
- 5.6 + 4 + 10 + 14 + 24 + 38 + 62 + 100 + 162 + 262 =
- 6.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?
- 7.Leapfrog list (each number is the sum of the two before it): 3, 8, 11, 19, 30, 49, 79, 128, 207, 335. What is 11 × the 7th number?
- 8.4 + 9 + 13 + 22 + 35 + 57 + 92 + 149 + 241 + 390 =
- 9.8 + 5 + 13 + 18 + 31 + 49 + 80 + 129 + 209 + 338 =
- 10.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?
- 11.1 + 1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 =
- 12.Leapfrog list (each number is the sum of the two before it): 5, 2, 7, 9, 16, 25, 41, 66, 107, 173. What is 11 × the 7th number?
- 13.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?
- 14.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?
- 15.4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 + 178 + 288 =
- 16.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?
- 17.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?
- 18.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?
- 19.2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 =
- 20.Leapfrog list (each number is the sum of the two before it): 4, 3, 7, 10, 17, 27, 44, 71, 115, 186. What is 11 × the 7th number?
- 21.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?
- 22.3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 + 369 =
- 23.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?
- 24.6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 + 398 =
- 25.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?
- 26.9 + 2 + 11 + 13 + 24 + 37 + 61 + 98 + 159 + 257 =
- 27.A leapfrog list starts 2, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 28.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?
- 29.Leapfrog list (each number is the sum of the two before it): 4, 9, 13, 22, 35, 57, 92, 149, 241, 390. What is 11 × the 7th number?
- 30.3 + 8 + 11 + 19 + 30 + 49 + 79 + 128 + 207 + 335 =
- 31.7 + 5 + 12 + 17 + 29 + 46 + 75 + 121 + 196 + 317 =
- 32.Leapfrog list (each number is the sum of the two before it): 8, 1, 9, 10, 19, 29, 48, 77, 125, 202. What is 11 × the 7th number?
- 33.3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 + 199 =
- 34.8 + 4 + 12 + 16 + 28 + 44 + 72 + 116 + 188 + 304 =
- 35.A leapfrog list starts 3, 5 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, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 37.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?
- 38.6 + 2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 =
- 39.A leapfrog list starts 4, 5 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
- 957
- 858
- 308
- 198
- 682
- 308
- 869
- 1012
- 880
- 1111
- 143
- 451
- 759
- 1111
- 748
- 1232
- 572
- 1144
- 550
- 484
- 143
- 957
- 1056
- 1034
- 396
- 671
- 374
- 550
- 1012
- 869
- 825
- 528
- 517
- 792
- 605
- 1177
- 1122
- 506
- 660
- 1287
Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks