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): 8, 7, 15, 22, 37, 59, 96, 155, 251, 406. What is 11 × the 7th number?
- 2.Leapfrog list (each number is the sum of the two before it): 8, 9, 17, 26, 43, 69, 112, 181, 293, 474. What is 11 × the 7th number?
- 3.A leapfrog list starts 9, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 4.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?
- 5.2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 + 348 =
- 6.2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 + 178 =
- 7.Leapfrog list (each number is the sum of the two before it): 7, 7, 14, 21, 35, 56, 91, 147, 238, 385. What is 11 × the 7th number?
- 8.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?
- 9.A leapfrog list starts 3, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 10.4 + 4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 =
- 11.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?
- 12.3 + 2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 =
- 13.A leapfrog list starts 8, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 14.7 + 2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 =
- 15.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?
- 16.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?
- 17.Leapfrog list (each number is the sum of the two before it): 5, 8, 13, 21, 34, 55, 89, 144, 233, 377. What is 11 × the 7th number?
- 18.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?
- 19.Leapfrog list (each number is the sum of the two before it): 1, 8, 9, 17, 26, 43, 69, 112, 181, 293. What is 11 × the 7th number?
- 20.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?
- 21.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?
- 22.6 + 3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 =
- 23.Leapfrog list (each number is the sum of the two before it): 1, 4, 5, 9, 14, 23, 37, 60, 97, 157. What is 11 × the 7th number?
- 24.4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 + 178 + 288 =
- 25.A leapfrog list starts 8, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 26.A leapfrog list starts 1, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 27.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?
- 28.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?
- 29.5 + 4 + 9 + 13 + 22 + 35 + 57 + 92 + 149 + 241 =
- 30.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?
- 31.9 + 9 + 18 + 27 + 45 + 72 + 117 + 189 + 306 + 495 =
- 32.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?
- 33.9 + 5 + 14 + 19 + 33 + 52 + 85 + 137 + 222 + 359 =
- 34.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?
- 35.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?
- 36.8 + 3 + 11 + 14 + 25 + 39 + 64 + 103 + 167 + 270 =
- 37.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?
- 38.3 + 3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 =
- 39.8 + 2 + 10 + 12 + 22 + 34 + 56 + 90 + 146 + 236 =
- 40.9 + 4 + 13 + 17 + 30 + 47 + 77 + 124 + 201 + 325 =
Answer key
- 1056
- 1232
- 759
- 1199
- 902
- 462
- 1001
- 891
- 781
- 572
- 781
- 341
- 880
- 561
- 671
- 1067
- 979
- 286
- 759
- 484
- 253
- 594
- 407
- 748
- 968
- 583
- 374
- 748
- 627
- 396
- 1287
- 473
- 935
- 528
- 693
- 704
- 1122
- 429
- 616
- 847
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