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, 5, 7, 12, 19, 31, 50, 81, 131, 212. What is 11 × the 7th number?
- 2.7 + 2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 =
- 3.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?
- 4.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?
- 5.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?
- 6.9 + 9 + 18 + 27 + 45 + 72 + 117 + 189 + 306 + 495 =
- 7.2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 =
- 8.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?
- 9.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?
- 10.Leapfrog list (each number is the sum of the two before it): 9, 7, 16, 23, 39, 62, 101, 163, 264, 427. What is 11 × the 7th number?
- 11.Leapfrog list (each number is the sum of the two before it): 8, 3, 11, 14, 25, 39, 64, 103, 167, 270. What is 11 × the 7th number?
- 12.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?
- 13.Leapfrog list (each number is the sum of the two before it): 6, 4, 10, 14, 24, 38, 62, 100, 162, 262. What is 11 × the 7th number?
- 14.6 + 3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 =
- 15.6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 + 225 + 364 =
- 16.A leapfrog list starts 6, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 17.3 + 3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 =
- 18.8 + 4 + 12 + 16 + 28 + 44 + 72 + 116 + 188 + 304 =
- 19.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?
- 20.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?
- 21.Leapfrog list (each number is the sum of the two before it): 8, 4, 12, 16, 28, 44, 72, 116, 188, 304. What is 11 × the 7th number?
- 22.A leapfrog list starts 1, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 23.3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 + 369 =
- 24.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?
- 25.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?
- 26.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?
- 27.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?
- 28.A leapfrog list starts 7, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 29.3 + 1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 =
- 30.2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 + 348 =
- 31.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?
- 32.7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 + 259 + 419 =
- 33.Leapfrog list (each number is the sum of the two before it): 8, 2, 10, 12, 22, 34, 56, 90, 146, 236. What is 11 × the 7th number?
- 34.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?
- 35.9 + 2 + 11 + 13 + 24 + 37 + 61 + 98 + 159 + 257 =
- 36.4 + 1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 =
- 37.9 + 6 + 15 + 21 + 36 + 57 + 93 + 150 + 243 + 393 =
- 38.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?
- 39.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?
- 40.Leapfrog list (each number is the sum of the two before it): 6, 3, 9, 12, 21, 33, 54, 87, 141, 228. What is 11 × the 7th number?
Answer key
- 550
- 561
- 770
- 968
- 143
- 1287
- 374
- 407
- 902
- 1111
- 704
- 473
- 682
- 594
- 946
- 594
- 429
- 792
- 1001
- 649
- 792
- 847
- 957
- 748
- 286
- 946
- 715
- 1177
- 253
- 902
- 649
- 1089
- 616
- 231
- 671
- 308
- 1023
- 693
- 451
- 594
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