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, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 2.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?
- 3.8 + 3 + 11 + 14 + 25 + 39 + 64 + 103 + 167 + 270 =
- 4.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?
- 5.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?
- 6.A leapfrog list starts 3, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 7.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?
- 8.3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 + 369 =
- 9.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?
- 10.A leapfrog list starts 1, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 11.7 + 1 + 8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 =
- 12.8 + 8 + 16 + 24 + 40 + 64 + 104 + 168 + 272 + 440 =
- 13.2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 =
- 14.3 + 3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 =
- 15.2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 =
- 16.6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 + 398 =
- 17.1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 =
- 18.1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 + 327 =
- 19.Leapfrog list (each number is the sum of the two before it): 4, 9, 13, 22, 35, 57, 92, 149, 241, 390. What is 11 × the 7th number?
- 20.2 + 2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 =
- 21.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?
- 22.A leapfrog list starts 9, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 23.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?
- 24.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?
- 25.2 + 1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 =
- 26.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?
- 27.3 + 2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 =
- 28.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?
- 29.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?
- 30.A leapfrog list starts 4, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 31.6 + 4 + 10 + 14 + 24 + 38 + 62 + 100 + 162 + 262 =
- 32.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?
- 33.6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 + 225 + 364 =
- 34.Leapfrog list (each number is the sum of the two before it): 7, 9, 16, 25, 41, 66, 107, 173, 280, 453. What is 11 × the 7th number?
- 35.9 + 9 + 18 + 27 + 45 + 72 + 117 + 189 + 306 + 495 =
- 36.5 + 1 + 6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 =
- 37.A leapfrog list starts 8, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 38.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?
- 39.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?
- 40.1 + 1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 =
Answer key
- 539
- 143
- 704
- 638
- 902
- 341
- 407
- 957
- 957
- 759
- 473
- 1144
- 550
- 429
- 726
- 1034
- 407
- 847
- 1012
- 286
- 429
- 1023
- 792
- 594
- 198
- 671
- 341
- 1067
- 231
- 396
- 682
- 473
- 946
- 1177
- 1287
- 363
- 792
- 968
- 198
- 143
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