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.Leapfrog list (each number is the sum of the two before it): 7, 1, 8, 9, 17, 26, 43, 69, 112, 181. What is 11 × the 7th number?
- 2.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?
- 3.9 + 7 + 16 + 23 + 39 + 62 + 101 + 163 + 264 + 427 =
- 4.8 + 2 + 10 + 12 + 22 + 34 + 56 + 90 + 146 + 236 =
- 5.5 + 4 + 9 + 13 + 22 + 35 + 57 + 92 + 149 + 241 =
- 6.2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 + 314 =
- 7.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?
- 8.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?
- 9.5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 + 309 =
- 10.Leapfrog list (each number is the sum of the two before it): 1, 6, 7, 13, 20, 33, 53, 86, 139, 225. What is 11 × the 7th number?
- 11.5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 + 233 + 377 =
- 12.1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 =
- 13.3 + 2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 =
- 14.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?
- 15.1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 =
- 16.7 + 3 + 10 + 13 + 23 + 36 + 59 + 95 + 154 + 249 =
- 17.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?
- 18.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?
- 19.A leapfrog list starts 7, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 20.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?
- 21.Leapfrog list (each number is the sum of the two before it): 5, 6, 11, 17, 28, 45, 73, 118, 191, 309. What is 11 × the 7th number?
- 22.6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 + 398 =
- 23.4 + 1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 =
- 24.Leapfrog list (each number is the sum of the two before it): 9, 5, 14, 19, 33, 52, 85, 137, 222, 359. What is 11 × the 7th number?
- 25.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?
- 26.3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 + 369 =
- 27.8 + 6 + 14 + 20 + 34 + 54 + 88 + 142 + 230 + 372 =
- 28.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?
- 29.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?
- 30.6 + 5 + 11 + 16 + 27 + 43 + 70 + 113 + 183 + 296 =
- 31.A leapfrog list starts 3, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 32.6 + 4 + 10 + 14 + 24 + 38 + 62 + 100 + 162 + 262 =
- 33.8 + 8 + 16 + 24 + 40 + 64 + 104 + 168 + 272 + 440 =
- 34.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?
- 35.A leapfrog list starts 5, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 36.8 + 1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 =
- 37.2 + 1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 =
- 38.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?
- 39.Leapfrog list (each number is the sum of the two before it): 3, 2, 5, 7, 12, 19, 31, 50, 81, 131. What is 11 × the 7th number?
- 40.A leapfrog list starts 9, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
Answer key
- 473
- 649
- 1111
- 616
- 627
- 814
- 660
- 484
- 803
- 583
- 979
- 495
- 341
- 671
- 319
- 649
- 429
- 759
- 473
- 660
- 803
- 1034
- 308
- 935
- 418
- 957
- 968
- 451
- 869
- 770
- 253
- 682
- 1144
- 374
- 803
- 528
- 198
- 638
- 341
- 1199
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