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
- 1.2 + 1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 =
- 2.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?
- 3.7 + 4 + 11 + 15 + 26 + 41 + 67 + 108 + 175 + 283 =
- 4.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?
- 5.A leapfrog list starts 2, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 6.1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 =
- 7.9 + 6 + 15 + 21 + 36 + 57 + 93 + 150 + 243 + 393 =
- 8.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?
- 9.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?
- 10.Leapfrog list (each number is the sum of the two before it): 8, 3, 11, 14, 25, 39, 64, 103, 167, 270. What is 11 × the 7th number?
- 11.A leapfrog list starts 6, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 12.Leapfrog list (each number is the sum of the two before it): 7, 8, 15, 23, 38, 61, 99, 160, 259, 419. What is 11 × the 7th number?
- 13.7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 + 453 =
- 14.3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 + 233 =
- 15.Leapfrog list (each number is the sum of the two before it): 3, 6, 9, 15, 24, 39, 63, 102, 165, 267. What is 11 × the 7th number?
- 16.6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 + 398 =
- 17.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?
- 18.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?
- 19.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?
- 20.6 + 1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 =
- 21.A leapfrog list starts 9, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 22.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?
- 23.3 + 2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 =
- 24.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?
- 25.2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 =
- 26.A leapfrog list starts 1, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 27.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?
- 28.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?
- 29.8 + 3 + 11 + 14 + 25 + 39 + 64 + 103 + 167 + 270 =
- 30.4 + 3 + 7 + 10 + 17 + 27 + 44 + 71 + 115 + 186 =
- 31.6 + 2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 =
- 32.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?
- 33.5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 + 309 =
- 34.A leapfrog list starts 8, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 35.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?
- 36.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?
- 37.4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 + 254 =
- 38.A leapfrog list starts 5, 8 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 7, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 40.1 + 1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 =
Answer key
- 198
- 803
- 737
- 825
- 814
- 319
- 1023
- 935
- 594
- 704
- 1034
- 1089
- 1177
- 605
- 693
- 1034
- 814
- 671
- 550
- 418
- 847
- 418
- 341
- 143
- 374
- 319
- 660
- 506
- 704
- 484
- 506
- 847
- 803
- 792
- 979
- 1232
- 660
- 979
- 825
- 143
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