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 8, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 2.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?
- 3.3 + 3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 =
- 4.3 + 8 + 11 + 19 + 30 + 49 + 79 + 128 + 207 + 335 =
- 5.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?
- 6.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?
- 7.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?
- 8.7 + 2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 =
- 9.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?
- 10.Leapfrog list (each number is the sum of the two before it): 9, 5, 14, 19, 33, 52, 85, 137, 222, 359. What is 11 × the 7th number?
- 11.9 + 6 + 15 + 21 + 36 + 57 + 93 + 150 + 243 + 393 =
- 12.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?
- 13.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?
- 14.2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 + 314 =
- 15.8 + 8 + 16 + 24 + 40 + 64 + 104 + 168 + 272 + 440 =
- 16.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?
- 17.6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 + 225 + 364 =
- 18.A leapfrog list starts 3, 2 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 5, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 20.A leapfrog list starts 8, 1 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): 7, 8, 15, 23, 38, 61, 99, 160, 259, 419. What is 11 × the 7th number?
- 22.1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 + 327 =
- 23.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?
- 24.5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 + 309 =
- 25.7 + 3 + 10 + 13 + 23 + 36 + 59 + 95 + 154 + 249 =
- 26.6 + 6 + 12 + 18 + 30 + 48 + 78 + 126 + 204 + 330 =
- 27.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?
- 28.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?
- 29.9 + 7 + 16 + 23 + 39 + 62 + 101 + 163 + 264 + 427 =
- 30.A leapfrog list starts 2, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 31.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?
- 32.Leapfrog list (each number is the sum of the two before it): 2, 2, 4, 6, 10, 16, 26, 42, 68, 110. What is 11 × the 7th number?
- 33.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?
- 34.A leapfrog list starts 9, 7 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): 3, 9, 12, 21, 33, 54, 87, 141, 228, 369. What is 11 × the 7th number?
- 36.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?
- 37.1 + 1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 =
- 38.A leapfrog list starts 7, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 39.3 + 2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 =
- 40.4 + 3 + 7 + 10 + 17 + 27 + 44 + 71 + 115 + 186 =
Answer key
- 1232
- 484
- 429
- 869
- 770
- 1199
- 825
- 561
- 825
- 935
- 1023
- 539
- 748
- 814
- 1144
- 748
- 946
- 341
- 1067
- 528
- 1089
- 847
- 363
- 803
- 649
- 858
- 924
- 693
- 1111
- 198
- 671
- 286
- 759
- 1111
- 957
- 605
- 143
- 1001
- 341
- 484
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