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 6, 2 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 6, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 3.7 + 3 + 10 + 13 + 23 + 36 + 59 + 95 + 154 + 249 =
- 4.9 + 2 + 11 + 13 + 24 + 37 + 61 + 98 + 159 + 257 =
- 5.9 + 3 + 12 + 15 + 27 + 42 + 69 + 111 + 180 + 291 =
- 6.A leapfrog list starts 5, 1 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, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 8.8 + 5 + 13 + 18 + 31 + 49 + 80 + 129 + 209 + 338 =
- 9.3 + 2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 =
- 10.5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 + 309 =
- 11.A leapfrog list starts 2, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 12.Leapfrog list (each number is the sum of the two before it): 9, 4, 13, 17, 30, 47, 77, 124, 201, 325. What is 11 × the 7th number?
- 13.2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 + 348 =
- 14.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?
- 15.2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 + 178 =
- 16.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?
- 17.Leapfrog list (each number is the sum of the two before it): 5, 5, 10, 15, 25, 40, 65, 105, 170, 275. What is 11 × the 7th number?
- 18.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?
- 19.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?
- 20.Leapfrog list (each number is the sum of the two before it): 1, 3, 4, 7, 11, 18, 29, 47, 76, 123. What is 11 × the 7th number?
- 21.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?
- 22.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?
- 23.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?
- 24.8 + 4 + 12 + 16 + 28 + 44 + 72 + 116 + 188 + 304 =
- 25.Leapfrog list (each number is the sum of the two before it): 7, 5, 12, 17, 29, 46, 75, 121, 196, 317. What is 11 × the 7th number?
- 26.2 + 2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 =
- 27.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?
- 28.4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 + 199 + 322 =
- 29.1 + 8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 =
- 30.Leapfrog list (each number is the sum of the two before it): 4, 4, 8, 12, 20, 32, 52, 84, 136, 220. What is 11 × the 7th number?
- 31.A leapfrog list starts 4, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 32.A leapfrog list starts 1, 3 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): 2, 1, 3, 4, 7, 11, 18, 29, 47, 76. What is 11 × the 7th number?
- 34.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?
- 35.4 + 3 + 7 + 10 + 17 + 27 + 44 + 71 + 115 + 186 =
- 36.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?
- 37.A leapfrog list starts 4, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 38.9 + 7 + 16 + 23 + 39 + 62 + 101 + 163 + 264 + 427 =
- 39.6 + 1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 =
- 40.4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 + 254 =
Answer key
- 506
- 770
- 649
- 671
- 759
- 363
- 902
- 880
- 341
- 803
- 814
- 847
- 902
- 759
- 462
- 286
- 715
- 748
- 253
- 319
- 902
- 286
- 968
- 792
- 825
- 286
- 671
- 836
- 759
- 572
- 924
- 319
- 198
- 638
- 484
- 462
- 1012
- 1111
- 418
- 660
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