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 + 1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 =
- 2.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?
- 3.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?
- 4.A leapfrog list starts 5, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 5.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?
- 6.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?
- 7.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?
- 8.2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 + 178 =
- 9.1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 =
- 10.4 + 9 + 13 + 22 + 35 + 57 + 92 + 149 + 241 + 390 =
- 11.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?
- 12.2 + 6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 =
- 13.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?
- 14.6 + 3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 =
- 15.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?
- 16.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?
- 17.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?
- 18.2 + 1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 =
- 19.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?
- 20.A leapfrog list starts 4, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 21.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?
- 22.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?
- 23.5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 + 343 =
- 24.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?
- 25.A leapfrog list starts 5, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 26.Leapfrog list (each number is the sum of the two before it): 1, 5, 6, 11, 17, 28, 45, 73, 118, 191. What is 11 × the 7th number?
- 27.Leapfrog list (each number is the sum of the two before it): 5, 4, 9, 13, 22, 35, 57, 92, 149, 241. What is 11 × the 7th number?
- 28.2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 + 348 =
- 29.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?
- 30.7 + 2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 =
- 31.Leapfrog list (each number is the sum of the two before it): 9, 2, 11, 13, 24, 37, 61, 98, 159, 257. What is 11 × the 7th number?
- 32.9 + 8 + 17 + 25 + 42 + 67 + 109 + 176 + 285 + 461 =
- 33.2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 =
- 34.Leapfrog list (each number is the sum of the two before it): 1, 1, 2, 3, 5, 8, 13, 21, 34, 55. What is 11 × the 7th number?
- 35.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?
- 36.Leapfrog list (each number is the sum of the two before it): 6, 4, 10, 14, 24, 38, 62, 100, 162, 262. What is 11 × the 7th number?
- 37.9 + 5 + 14 + 19 + 33 + 52 + 85 + 137 + 222 + 359 =
- 38.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?
- 39.9 + 1 + 10 + 11 + 21 + 32 + 53 + 85 + 138 + 223 =
- 40.3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 + 199 =
Answer key
- 143
- 363
- 198
- 1067
- 517
- 616
- 231
- 462
- 319
- 1012
- 594
- 638
- 583
- 594
- 748
- 253
- 825
- 198
- 671
- 484
- 924
- 308
- 891
- 847
- 363
- 495
- 627
- 902
- 429
- 561
- 671
- 1199
- 550
- 143
- 902
- 682
- 935
- 308
- 583
- 517
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