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.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?
- 2.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?
- 3.3 + 1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 =
- 4.2 + 2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 =
- 5.6 + 2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 =
- 6.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?
- 7.5 + 1 + 6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 =
- 8.7 + 4 + 11 + 15 + 26 + 41 + 67 + 108 + 175 + 283 =
- 9.A leapfrog list starts 2, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 10.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?
- 11.A leapfrog list starts 9, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 12.8 + 4 + 12 + 16 + 28 + 44 + 72 + 116 + 188 + 304 =
- 13.1 + 6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 + 225 =
- 14.Leapfrog list (each number is the sum of the two before it): 6, 5, 11, 16, 27, 43, 70, 113, 183, 296. What is 11 × the 7th number?
- 15.Leapfrog list (each number is the sum of the two before it): 6, 1, 7, 8, 15, 23, 38, 61, 99, 160. What is 11 × the 7th number?
- 16.1 + 1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 =
- 17.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?
- 18.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?
- 19.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?
- 20.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?
- 21.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?
- 22.Leapfrog list (each number is the sum of the two before it): 8, 4, 12, 16, 28, 44, 72, 116, 188, 304. What is 11 × the 7th number?
- 23.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?
- 24.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?
- 25.Leapfrog list (each number is the sum of the two before it): 3, 4, 7, 11, 18, 29, 47, 76, 123, 199. What is 11 × the 7th number?
- 26.A leapfrog list starts 4, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 27.6 + 3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 =
- 28.4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 + 254 =
- 29.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?
- 30.6 + 4 + 10 + 14 + 24 + 38 + 62 + 100 + 162 + 262 =
- 31.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?
- 32.Leapfrog list (each number is the sum of the two before it): 3, 2, 5, 7, 12, 19, 31, 50, 81, 131. What is 11 × the 7th number?
- 33.1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 =
- 34.Leapfrog list (each number is the sum of the two before it): 3, 1, 4, 5, 9, 14, 23, 37, 60, 97. What is 11 × the 7th number?
- 35.1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 =
- 36.4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 + 356 =
- 37.Leapfrog list (each number is the sum of the two before it): 6, 6, 12, 18, 30, 48, 78, 126, 204, 330. What is 11 × the 7th number?
- 38.Leapfrog list (each number is the sum of the two before it): 4, 6, 10, 16, 26, 42, 68, 110, 178, 288. What is 11 × the 7th number?
- 39.7 + 2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 =
- 40.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?
Answer key
- 825
- 671
- 253
- 286
- 506
- 847
- 363
- 737
- 374
- 1122
- 1287
- 792
- 583
- 770
- 418
- 143
- 143
- 594
- 847
- 924
- 891
- 792
- 693
- 605
- 517
- 836
- 594
- 660
- 451
- 682
- 396
- 341
- 495
- 253
- 407
- 924
- 858
- 748
- 561
- 1023
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