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 5, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 2.7 + 3 + 10 + 13 + 23 + 36 + 59 + 95 + 154 + 249 =
- 3.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?
- 4.2 + 1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 =
- 5.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?
- 6.Leapfrog list (each number is the sum of the two before it): 5, 5, 10, 15, 25, 40, 65, 105, 170, 275. What is 11 × the 7th number?
- 7.4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 + 356 =
- 8.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?
- 9.A leapfrog list starts 5, 2 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 8, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 11.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?
- 12.5 + 2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 =
- 13.A leapfrog list starts 5, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 14.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?
- 15.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?
- 16.6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 + 267 + 432 =
- 17.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?
- 18.8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 + 474 =
- 19.6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 + 225 + 364 =
- 20.A leapfrog list starts 2, 2 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, 1, 8, 9, 17, 26, 43, 69, 112, 181. What is 11 × the 7th number?
- 22.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?
- 23.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?
- 24.A leapfrog list starts 6, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 25.Leapfrog list (each number is the sum of the two before it): 3, 7, 10, 17, 27, 44, 71, 115, 186, 301. What is 11 × the 7th number?
- 26.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?
- 27.8 + 3 + 11 + 14 + 25 + 39 + 64 + 103 + 167 + 270 =
- 28.1 + 1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 =
- 29.9 + 2 + 11 + 13 + 24 + 37 + 61 + 98 + 159 + 257 =
- 30.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?
- 31.6 + 4 + 10 + 14 + 24 + 38 + 62 + 100 + 162 + 262 =
- 32.7 + 7 + 14 + 21 + 35 + 56 + 91 + 147 + 238 + 385 =
- 33.A leapfrog list starts 7, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 34.2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 =
- 35.4 + 1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 =
- 36.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?
- 37.A leapfrog list starts 4, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 38.8 + 6 + 14 + 20 + 34 + 54 + 88 + 142 + 230 + 372 =
- 39.8 + 5 + 13 + 18 + 31 + 49 + 80 + 129 + 209 + 338 =
- 40.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?
Answer key
- 715
- 649
- 143
- 198
- 935
- 715
- 924
- 484
- 451
- 616
- 231
- 451
- 979
- 957
- 462
- 1122
- 605
- 1232
- 946
- 286
- 473
- 1122
- 539
- 682
- 781
- 363
- 704
- 143
- 671
- 429
- 682
- 1001
- 473
- 374
- 308
- 748
- 660
- 968
- 880
- 143
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