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 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 =
- 2.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?
- 3.7 + 5 + 12 + 17 + 29 + 46 + 75 + 121 + 196 + 317 =
- 4.Leapfrog list (each number is the sum of the two before it): 1, 2, 3, 5, 8, 13, 21, 34, 55, 89. What is 11 × the 7th number?
- 5.A leapfrog list starts 3, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 6.6 + 3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 =
- 7.4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 + 356 =
- 8.3 + 3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 =
- 9.A leapfrog list starts 8, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 10.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?
- 11.A leapfrog list starts 4, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 12.A leapfrog list starts 7, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 13.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?
- 14.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?
- 15.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?
- 16.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?
- 17.8 + 1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 =
- 18.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?
- 19.Leapfrog list (each number is the sum of the two before it): 7, 5, 12, 17, 29, 46, 75, 121, 196, 317. What is 11 × the 7th number?
- 20.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?
- 21.2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 =
- 22.7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 + 259 + 419 =
- 23.9 + 9 + 18 + 27 + 45 + 72 + 117 + 189 + 306 + 495 =
- 24.1 + 8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 =
- 25.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?
- 26.9 + 7 + 16 + 23 + 39 + 62 + 101 + 163 + 264 + 427 =
- 27.2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 =
- 28.7 + 3 + 10 + 13 + 23 + 36 + 59 + 95 + 154 + 249 =
- 29.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?
- 30.2 + 6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 =
- 31.Leapfrog list (each number is the sum of the two before it): 1, 3, 4, 7, 11, 18, 29, 47, 76, 123. What is 11 × the 7th number?
- 32.A leapfrog list starts 5, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 33.Leapfrog list (each number is the sum of the two before it): 3, 4, 7, 11, 18, 29, 47, 76, 123, 199. What is 11 × the 7th number?
- 34.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?
- 35.Leapfrog list (each number is the sum of the two before it): 1, 9, 10, 19, 29, 48, 77, 125, 202, 327. What is 11 × the 7th number?
- 36.Leapfrog list (each number is the sum of the two before it): 6, 3, 9, 12, 21, 33, 54, 87, 141, 228. What is 11 × the 7th number?
- 37.A leapfrog list starts 2, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 38.5 + 3 + 8 + 11 + 19 + 30 + 49 + 79 + 128 + 207 =
- 39.Leapfrog list (each number is the sum of the two before it): 2, 2, 4, 6, 10, 16, 26, 42, 68, 110. What is 11 × the 7th number?
- 40.Leapfrog list (each number is the sum of the two before it): 5, 1, 6, 7, 13, 20, 33, 53, 86, 139. What is 11 × the 7th number?
Answer key
- 407
- 341
- 825
- 231
- 693
- 594
- 924
- 429
- 704
- 484
- 924
- 1089
- 1111
- 308
- 671
- 1111
- 528
- 528
- 825
- 418
- 726
- 1089
- 1287
- 759
- 1012
- 1111
- 374
- 649
- 1232
- 638
- 319
- 715
- 517
- 429
- 847
- 594
- 198
- 539
- 286
- 363
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