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): 2, 3, 5, 8, 13, 21, 34, 55, 89, 144. What is 11 × the 7th number?
- 2.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?
- 3.Leapfrog list (each number is the sum of the two before it): 9, 1, 10, 11, 21, 32, 53, 85, 138, 223. What is 11 × the 7th number?
- 4.A leapfrog list starts 3, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 5.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?
- 6.A leapfrog list starts 5, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 7.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?
- 8.Leapfrog list (each number is the sum of the two before it): 2, 6, 8, 14, 22, 36, 58, 94, 152, 246. What is 11 × the 7th number?
- 9.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?
- 10.Leapfrog list (each number is the sum of the two before it): 7, 3, 10, 13, 23, 36, 59, 95, 154, 249. What is 11 × the 7th number?
- 11.6 + 1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 =
- 12.3 + 7 + 10 + 17 + 27 + 44 + 71 + 115 + 186 + 301 =
- 13.7 + 4 + 11 + 15 + 26 + 41 + 67 + 108 + 175 + 283 =
- 14.3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 + 267 =
- 15.6 + 2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 =
- 16.5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 + 343 =
- 17.3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 + 369 =
- 18.Leapfrog list (each number is the sum of the two before it): 2, 5, 7, 12, 19, 31, 50, 81, 131, 212. What is 11 × the 7th number?
- 19.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?
- 20.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?
- 21.Leapfrog list (each number is the sum of the two before it): 8, 1, 9, 10, 19, 29, 48, 77, 125, 202. What is 11 × the 7th number?
- 22.5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 + 233 + 377 =
- 23.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?
- 24.1 + 6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 + 225 =
- 25.8 + 2 + 10 + 12 + 22 + 34 + 56 + 90 + 146 + 236 =
- 26.Leapfrog list (each number is the sum of the two before it): 3, 4, 7, 11, 18, 29, 47, 76, 123, 199. What is 11 × the 7th number?
- 27.2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 =
- 28.2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 =
- 29.5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 + 309 =
- 30.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?
- 31.Leapfrog list (each number is the sum of the two before it): 6, 1, 7, 8, 15, 23, 38, 61, 99, 160. What is 11 × the 7th number?
- 32.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?
- 33.Leapfrog list (each number is the sum of the two before it): 9, 6, 15, 21, 36, 57, 93, 150, 243, 393. What is 11 × the 7th number?
- 34.9 + 6 + 15 + 21 + 36 + 57 + 93 + 150 + 243 + 393 =
- 35.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?
- 36.8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 + 474 =
- 37.2 + 2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 =
- 38.A leapfrog list starts 1, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 39.A leapfrog list starts 9, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 40.Leapfrog list (each number is the sum of the two before it): 2, 4, 6, 10, 16, 26, 42, 68, 110, 178. What is 11 × the 7th number?
Answer key
- 374
- 539
- 583
- 429
- 715
- 891
- 462
- 638
- 770
- 649
- 418
- 781
- 737
- 693
- 506
- 891
- 957
- 550
- 1067
- 726
- 528
- 979
- 1122
- 583
- 616
- 517
- 550
- 374
- 803
- 517
- 418
- 968
- 1023
- 1023
- 143
- 1232
- 286
- 671
- 583
- 462
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