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): 6, 6, 12, 18, 30, 48, 78, 126, 204, 330. What is 11 × the 7th number?
- 2.8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 + 474 =
- 3.Leapfrog list (each number is the sum of the two before it): 1, 6, 7, 13, 20, 33, 53, 86, 139, 225. What is 11 × the 7th number?
- 4.3 + 7 + 10 + 17 + 27 + 44 + 71 + 115 + 186 + 301 =
- 5.A leapfrog list starts 4, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 6.4 + 2 + 6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 =
- 7.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?
- 8.Leapfrog list (each number is the sum of the two before it): 6, 2, 8, 10, 18, 28, 46, 74, 120, 194. What is 11 × the 7th number?
- 9.7 + 3 + 10 + 13 + 23 + 36 + 59 + 95 + 154 + 249 =
- 10.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?
- 11.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?
- 12.5 + 5 + 10 + 15 + 25 + 40 + 65 + 105 + 170 + 275 =
- 13.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?
- 14.A leapfrog list starts 6, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 15.Leapfrog list (each number is the sum of the two before it): 4, 7, 11, 18, 29, 47, 76, 123, 199, 322. What is 11 × the 7th number?
- 16.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?
- 17.A leapfrog list starts 8, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 18.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?
- 19.1 + 6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 + 225 =
- 20.9 + 2 + 11 + 13 + 24 + 37 + 61 + 98 + 159 + 257 =
- 21.Leapfrog list (each number is the sum of the two before it): 1, 9, 10, 19, 29, 48, 77, 125, 202, 327. What is 11 × the 7th number?
- 22.9 + 8 + 17 + 25 + 42 + 67 + 109 + 176 + 285 + 461 =
- 23.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?
- 24.4 + 4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 =
- 25.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?
- 26.8 + 4 + 12 + 16 + 28 + 44 + 72 + 116 + 188 + 304 =
- 27.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?
- 28.1 + 8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 =
- 29.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?
- 30.8 + 5 + 13 + 18 + 31 + 49 + 80 + 129 + 209 + 338 =
- 31.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?
- 32.4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 + 356 =
- 33.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?
- 34.A leapfrog list starts 5, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 35.A leapfrog list starts 7, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 36.6 + 2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 =
- 37.4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 + 199 + 322 =
- 38.9 + 6 + 15 + 21 + 36 + 57 + 93 + 150 + 243 + 393 =
- 39.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?
- 40.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?
Answer key
- 858
- 1232
- 583
- 781
- 748
- 396
- 1012
- 506
- 649
- 594
- 473
- 715
- 286
- 946
- 836
- 792
- 616
- 396
- 583
- 671
- 847
- 1199
- 814
- 572
- 319
- 792
- 891
- 759
- 198
- 880
- 979
- 924
- 594
- 803
- 1089
- 506
- 836
- 1023
- 143
- 143
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