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.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?
- 2.5 + 5 + 10 + 15 + 25 + 40 + 65 + 105 + 170 + 275 =
- 3.Leapfrog list (each number is the sum of the two before it): 2, 3, 5, 8, 13, 21, 34, 55, 89, 144. What is 11 × the 7th number?
- 4.A leapfrog list starts 3, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 5.Leapfrog list (each number is the sum of the two before it): 9, 4, 13, 17, 30, 47, 77, 124, 201, 325. What is 11 × the 7th number?
- 6.A leapfrog list starts 1, 7 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 3, 7 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): 5, 6, 11, 17, 28, 45, 73, 118, 191, 309. What is 11 × the 7th number?
- 9.Leapfrog list (each number is the sum of the two before it): 5, 2, 7, 9, 16, 25, 41, 66, 107, 173. What is 11 × the 7th number?
- 10.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?
- 11.A leapfrog list starts 8, 5 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 2, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 13.1 + 1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 =
- 14.Leapfrog list (each number is the sum of the two before it): 9, 3, 12, 15, 27, 42, 69, 111, 180, 291. What is 11 × the 7th number?
- 15.A leapfrog list starts 9, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 16.2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 =
- 17.A leapfrog list starts 4, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 18.A leapfrog list starts 1, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 19.9 + 9 + 18 + 27 + 45 + 72 + 117 + 189 + 306 + 495 =
- 20.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?
- 21.8 + 2 + 10 + 12 + 22 + 34 + 56 + 90 + 146 + 236 =
- 22.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?
- 23.4 + 3 + 7 + 10 + 17 + 27 + 44 + 71 + 115 + 186 =
- 24.3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 + 233 =
- 25.6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 + 398 =
- 26.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?
- 27.Leapfrog list (each number is the sum of the two before it): 8, 2, 10, 12, 22, 34, 56, 90, 146, 236. What is 11 × the 7th number?
- 28.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?
- 29.Leapfrog list (each number is the sum of the two before it): 8, 8, 16, 24, 40, 64, 104, 168, 272, 440. What is 11 × the 7th number?
- 30.8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 + 474 =
- 31.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?
- 32.2 + 6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 =
- 33.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?
- 34.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?
- 35.9 + 3 + 12 + 15 + 27 + 42 + 69 + 111 + 180 + 291 =
- 36.A leapfrog list starts 6, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 37.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?
- 38.9 + 7 + 16 + 23 + 39 + 62 + 101 + 163 + 264 + 427 =
- 39.A leapfrog list starts 5, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 40.1 + 8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 =
Answer key
- 495
- 715
- 374
- 957
- 847
- 671
- 781
- 803
- 451
- 935
- 880
- 902
- 143
- 759
- 1023
- 374
- 396
- 847
- 1287
- 539
- 616
- 825
- 484
- 605
- 1034
- 429
- 616
- 231
- 1144
- 1232
- 308
- 638
- 517
- 363
- 759
- 682
- 803
- 1111
- 451
- 759
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