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
- 1.4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 + 356 =
- 2.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?
- 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.A leapfrog list starts 7, 6 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 7, 5 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 7, 1 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 1, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 8.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?
- 9.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?
- 10.A leapfrog list starts 4, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 11.2 + 2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 =
- 12.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?
- 13.A leapfrog list starts 1, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 14.7 + 1 + 8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 =
- 15.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?
- 16.2 + 1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 =
- 17.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?
- 18.3 + 2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 =
- 19.Leapfrog list (each number is the sum of the two before it): 2, 7, 9, 16, 25, 41, 66, 107, 173, 280. What is 11 × the 7th number?
- 20.Leapfrog list (each number is the sum of the two before it): 7, 9, 16, 25, 41, 66, 107, 173, 280, 453. What is 11 × the 7th number?
- 21.A leapfrog list starts 3, 7 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): 2, 2, 4, 6, 10, 16, 26, 42, 68, 110. What is 11 × the 7th number?
- 23.7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 + 453 =
- 24.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?
- 25.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?
- 26.A leapfrog list starts 6, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 27.A leapfrog list starts 2, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 28.1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 + 259 =
- 29.7 + 7 + 14 + 21 + 35 + 56 + 91 + 147 + 238 + 385 =
- 30.A leapfrog list starts 6, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 31.6 + 4 + 10 + 14 + 24 + 38 + 62 + 100 + 162 + 262 =
- 32.Leapfrog list (each number is the sum of the two before it): 6, 6, 12, 18, 30, 48, 78, 126, 204, 330. What is 11 × the 7th number?
- 33.6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 + 267 + 432 =
- 34.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?
- 35.5 + 5 + 10 + 15 + 25 + 40 + 65 + 105 + 170 + 275 =
- 36.Leapfrog list (each number is the sum of the two before it): 8, 9, 17, 26, 43, 69, 112, 181, 293, 474. What is 11 × the 7th number?
- 37.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?
- 38.3 + 8 + 11 + 19 + 30 + 49 + 79 + 128 + 207 + 335 =
- 39.5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 + 233 + 377 =
- 40.Leapfrog list (each number is the sum of the two before it): 5, 7, 12, 19, 31, 50, 81, 131, 212, 343. What is 11 × the 7th number?
Answer key
- 924
- 550
- 979
- 913
- 825
- 473
- 495
- 814
- 1287
- 836
- 286
- 858
- 407
- 473
- 253
- 198
- 715
- 341
- 726
- 1177
- 781
- 286
- 1177
- 253
- 924
- 946
- 462
- 671
- 1001
- 506
- 682
- 858
- 1122
- 880
- 715
- 1232
- 429
- 869
- 979
- 891
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