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
- 1.6 + 3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 =
- 2.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?
- 3.4 + 9 + 13 + 22 + 35 + 57 + 92 + 149 + 241 + 390 =
- 4.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?
- 5.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?
- 6.7 + 1 + 8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 =
- 7.A leapfrog list starts 1, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 8.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?
- 9.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?
- 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.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?
- 12.2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 =
- 13.Leapfrog list (each number is the sum of the two before it): 7, 2, 9, 11, 20, 31, 51, 82, 133, 215. What is 11 × the 7th number?
- 14.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?
- 15.1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 =
- 16.3 + 1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 =
- 17.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?
- 18.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?
- 19.5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 + 343 =
- 20.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?
- 21.A leapfrog list starts 2, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 22.5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 + 233 + 377 =
- 23.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?
- 24.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?
- 25.5 + 3 + 8 + 11 + 19 + 30 + 49 + 79 + 128 + 207 =
- 26.A leapfrog list starts 9, 5 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 3, 6 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): 4, 2, 6, 8, 14, 22, 36, 58, 94, 152. What is 11 × the 7th number?
- 29.8 + 6 + 14 + 20 + 34 + 54 + 88 + 142 + 230 + 372 =
- 30.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?
- 31.8 + 3 + 11 + 14 + 25 + 39 + 64 + 103 + 167 + 270 =
- 32.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?
- 33.A leapfrog list starts 7, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 34.Leapfrog list (each number is the sum of the two before it): 2, 1, 3, 4, 7, 11, 18, 29, 47, 76. What is 11 × the 7th number?
- 35.7 + 3 + 10 + 13 + 23 + 36 + 59 + 95 + 154 + 249 =
- 36.A leapfrog list starts 5, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 37.6 + 1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 =
- 38.A leapfrog list starts 6, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 39.A leapfrog list starts 3, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 40.3 + 7 + 10 + 17 + 27 + 44 + 71 + 115 + 186 + 301 =
Answer key
- 594
- 880
- 1012
- 616
- 143
- 473
- 231
- 715
- 1012
- 484
- 891
- 550
- 561
- 429
- 407
- 253
- 803
- 231
- 891
- 902
- 550
- 979
- 1089
- 198
- 539
- 935
- 693
- 396
- 968
- 924
- 704
- 605
- 1001
- 198
- 649
- 539
- 418
- 594
- 341
- 781
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