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
- 1.3 + 3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 =
- 2.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?
- 3.Leapfrog list (each number is the sum of the two before it): 9, 6, 15, 21, 36, 57, 93, 150, 243, 393. What is 11 × the 7th number?
- 4.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?
- 5.8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 + 474 =
- 6.8 + 3 + 11 + 14 + 25 + 39 + 64 + 103 + 167 + 270 =
- 7.A leapfrog list starts 1, 8 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 2, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 9.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?
- 10.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?
- 11.A leapfrog list starts 5, 1 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, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 13.8 + 4 + 12 + 16 + 28 + 44 + 72 + 116 + 188 + 304 =
- 14.4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 + 178 + 288 =
- 15.A leapfrog list starts 7, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 16.1 + 8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 =
- 17.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?
- 18.1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 + 327 =
- 19.1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 =
- 20.8 + 5 + 13 + 18 + 31 + 49 + 80 + 129 + 209 + 338 =
- 21.A leapfrog list starts 6, 9 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, 3, 12, 15, 27, 42, 69, 111, 180, 291. What is 11 × the 7th number?
- 23.8 + 7 + 15 + 22 + 37 + 59 + 96 + 155 + 251 + 406 =
- 24.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?
- 25.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?
- 26.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?
- 27.Leapfrog list (each number is the sum of the two before it): 7, 4, 11, 15, 26, 41, 67, 108, 175, 283. What is 11 × the 7th number?
- 28.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?
- 29.9 + 1 + 10 + 11 + 21 + 32 + 53 + 85 + 138 + 223 =
- 30.2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 + 314 =
- 31.4 + 1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 =
- 32.1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 =
- 33.4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 + 356 =
- 34.A leapfrog list starts 3, 3 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): 8, 6, 14, 20, 34, 54, 88, 142, 230, 372. What is 11 × the 7th number?
- 36.A leapfrog list starts 3, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 37.8 + 1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 =
- 38.3 + 2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 =
- 39.Leapfrog list (each number is the sum of the two before it): 1, 3, 4, 7, 11, 18, 29, 47, 76, 123. What is 11 × the 7th number?
- 40.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?
Answer key
- 429
- 693
- 1023
- 880
- 1232
- 704
- 759
- 814
- 143
- 374
- 363
- 462
- 792
- 748
- 737
- 759
- 825
- 847
- 231
- 880
- 1122
- 759
- 1056
- 1067
- 231
- 451
- 737
- 957
- 583
- 814
- 308
- 407
- 924
- 429
- 968
- 869
- 528
- 341
- 319
- 836
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