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): 5, 2, 7, 9, 16, 25, 41, 66, 107, 173. What is 11 × the 7th number?
- 2.7 + 1 + 8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 =
- 3.Leapfrog list (each number is the sum of the two before it): 8, 7, 15, 22, 37, 59, 96, 155, 251, 406. What is 11 × the 7th number?
- 4.8 + 8 + 16 + 24 + 40 + 64 + 104 + 168 + 272 + 440 =
- 5.4 + 4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 =
- 6.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?
- 7.1 + 1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 =
- 8.Leapfrog list (each number is the sum of the two before it): 1, 1, 2, 3, 5, 8, 13, 21, 34, 55. What is 11 × the 7th number?
- 9.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?
- 10.A leapfrog list starts 7, 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 6, 5 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): 3, 6, 9, 15, 24, 39, 63, 102, 165, 267. What is 11 × the 7th number?
- 13.2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 =
- 14.3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 + 267 =
- 15.5 + 1 + 6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 =
- 16.8 + 7 + 15 + 22 + 37 + 59 + 96 + 155 + 251 + 406 =
- 17.7 + 5 + 12 + 17 + 29 + 46 + 75 + 121 + 196 + 317 =
- 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.A leapfrog list starts 7, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 20.Leapfrog list (each number is the sum of the two before it): 4, 8, 12, 20, 32, 52, 84, 136, 220, 356. What is 11 × the 7th number?
- 21.A leapfrog list starts 2, 7 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): 1, 7, 8, 15, 23, 38, 61, 99, 160, 259. What is 11 × the 7th number?
- 23.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?
- 24.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?
- 25.8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 + 474 =
- 26.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?
- 27.5 + 4 + 9 + 13 + 22 + 35 + 57 + 92 + 149 + 241 =
- 28.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?
- 29.9 + 1 + 10 + 11 + 21 + 32 + 53 + 85 + 138 + 223 =
- 30.1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 =
- 31.A leapfrog list starts 3, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 32.A leapfrog list starts 3, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 33.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?
- 34.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?
- 35.9 + 9 + 18 + 27 + 45 + 72 + 117 + 189 + 306 + 495 =
- 36.5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 + 309 =
- 37.7 + 3 + 10 + 13 + 23 + 36 + 59 + 95 + 154 + 249 =
- 38.Leapfrog list (each number is the sum of the two before it): 3, 9, 12, 21, 33, 54, 87, 141, 228, 369. What is 11 × the 7th number?
- 39.Leapfrog list (each number is the sum of the two before it): 4, 3, 7, 10, 17, 27, 44, 71, 115, 186. What is 11 × the 7th number?
- 40.9 + 5 + 14 + 19 + 33 + 52 + 85 + 137 + 222 + 359 =
Answer key
- 451
- 473
- 1056
- 1144
- 572
- 1089
- 143
- 143
- 1034
- 1177
- 770
- 693
- 550
- 693
- 363
- 1056
- 825
- 594
- 561
- 924
- 726
- 671
- 396
- 429
- 1232
- 968
- 627
- 935
- 583
- 407
- 253
- 605
- 748
- 847
- 1287
- 803
- 649
- 957
- 484
- 935
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