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
- 1.9 + 5 + 14 + 19 + 33 + 52 + 85 + 137 + 222 + 359 =
- 2.9 + 7 + 16 + 23 + 39 + 62 + 101 + 163 + 264 + 427 =
- 3.8 + 8 + 16 + 24 + 40 + 64 + 104 + 168 + 272 + 440 =
- 4.Leapfrog list (each number is the sum of the two before it): 9, 8, 17, 25, 42, 67, 109, 176, 285, 461. What is 11 × the 7th number?
- 5.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?
- 6.A leapfrog list starts 9, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 7.2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 =
- 8.Leapfrog list (each number is the sum of the two before it): 4, 7, 11, 18, 29, 47, 76, 123, 199, 322. What is 11 × the 7th number?
- 9.3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 + 267 =
- 10.9 + 6 + 15 + 21 + 36 + 57 + 93 + 150 + 243 + 393 =
- 11.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?
- 12.5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 + 309 =
- 13.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?
- 14.Leapfrog list (each number is the sum of the two before it): 5, 3, 8, 11, 19, 30, 49, 79, 128, 207. What is 11 × the 7th number?
- 15.1 + 1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 =
- 16.A leapfrog list starts 4, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 17.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?
- 18.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?
- 19.Leapfrog list (each number is the sum of the two before it): 5, 9, 14, 23, 37, 60, 97, 157, 254, 411. What is 11 × the 7th number?
- 20.3 + 8 + 11 + 19 + 30 + 49 + 79 + 128 + 207 + 335 =
- 21.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?
- 22.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?
- 23.Leapfrog list (each number is the sum of the two before it): 6, 2, 8, 10, 18, 28, 46, 74, 120, 194. What is 11 × the 7th number?
- 24.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?
- 25.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?
- 26.A leapfrog list starts 4, 6 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): 8, 6, 14, 20, 34, 54, 88, 142, 230, 372. What is 11 × the 7th number?
- 28.Leapfrog list (each number is the sum of the two before it): 3, 5, 8, 13, 21, 34, 55, 89, 144, 233. What is 11 × the 7th number?
- 29.6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 + 267 + 432 =
- 30.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?
- 31.2 + 6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 =
- 32.Leapfrog list (each number is the sum of the two before it): 6, 8, 14, 22, 36, 58, 94, 152, 246, 398. What is 11 × the 7th number?
- 33.2 + 2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 =
- 34.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?
- 35.4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 + 356 =
- 36.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?
- 37.Leapfrog list (each number is the sum of the two before it): 6, 9, 15, 24, 39, 63, 102, 165, 267, 432. What is 11 × the 7th number?
- 38.7 + 1 + 8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 =
- 39.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?
- 40.A leapfrog list starts 6, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
Answer key
- 935
- 1111
- 1144
- 1199
- 451
- 671
- 550
- 836
- 693
- 1023
- 484
- 803
- 792
- 539
- 143
- 1012
- 847
- 1287
- 1067
- 869
- 935
- 671
- 506
- 550
- 957
- 748
- 968
- 605
- 1122
- 803
- 638
- 1034
- 286
- 561
- 924
- 396
- 1122
- 473
- 462
- 770
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