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): 1, 7, 8, 15, 23, 38, 61, 99, 160, 259. What is 11 × the 7th number?
- 2.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?
- 3.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?
- 4.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?
- 5.7 + 5 + 12 + 17 + 29 + 46 + 75 + 121 + 196 + 317 =
- 6.Leapfrog list (each number is the sum of the two before it): 5, 9, 14, 23, 37, 60, 97, 157, 254, 411. What is 11 × the 7th number?
- 7.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?
- 8.A leapfrog list starts 7, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 9.Leapfrog list (each number is the sum of the two before it): 5, 6, 11, 17, 28, 45, 73, 118, 191, 309. What is 11 × the 7th number?
- 10.6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 + 267 + 432 =
- 11.8 + 8 + 16 + 24 + 40 + 64 + 104 + 168 + 272 + 440 =
- 12.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?
- 13.A leapfrog list starts 1, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 14.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?
- 15.6 + 2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 =
- 16.Leapfrog list (each number is the sum of the two before it): 4, 1, 5, 6, 11, 17, 28, 45, 73, 118. What is 11 × the 7th number?
- 17.Leapfrog list (each number is the sum of the two before it): 9, 9, 18, 27, 45, 72, 117, 189, 306, 495. What is 11 × the 7th number?
- 18.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?
- 19.A leapfrog list starts 2, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 20.5 + 1 + 6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 =
- 21.A leapfrog list starts 3, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 22.7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 + 453 =
- 23.Leapfrog list (each number is the sum of the two before it): 9, 2, 11, 13, 24, 37, 61, 98, 159, 257. What is 11 × the 7th number?
- 24.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?
- 25.8 + 6 + 14 + 20 + 34 + 54 + 88 + 142 + 230 + 372 =
- 26.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?
- 27.6 + 1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 =
- 28.Leapfrog list (each number is the sum of the two before it): 2, 9, 11, 20, 31, 51, 82, 133, 215, 348. What is 11 × the 7th number?
- 29.4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 + 199 + 322 =
- 30.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?
- 31.4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 + 254 =
- 32.Leapfrog list (each number is the sum of the two before it): 6, 7, 13, 20, 33, 53, 86, 139, 225, 364. What is 11 × the 7th number?
- 33.Leapfrog list (each number is the sum of the two before it): 2, 7, 9, 16, 25, 41, 66, 107, 173, 280. What is 11 × the 7th number?
- 34.A leapfrog list starts 7, 6 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): 1, 2, 3, 5, 8, 13, 21, 34, 55, 89. What is 11 × the 7th number?
- 36.4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 + 356 =
- 37.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?
- 38.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?
- 39.6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 + 225 + 364 =
- 40.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?
Answer key
- 671
- 693
- 957
- 726
- 825
- 1067
- 858
- 649
- 803
- 1122
- 1144
- 1001
- 231
- 968
- 506
- 308
- 1287
- 671
- 550
- 363
- 517
- 1177
- 671
- 924
- 968
- 341
- 418
- 902
- 836
- 1199
- 660
- 946
- 726
- 913
- 231
- 924
- 891
- 198
- 946
- 979
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