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): 8, 7, 15, 22, 37, 59, 96, 155, 251, 406. What is 11 × the 7th number?
- 2.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?
- 3.Leapfrog list (each number is the sum of the two before it): 6, 8, 14, 22, 36, 58, 94, 152, 246, 398. What is 11 × the 7th number?
- 4.5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 + 254 + 411 =
- 5.A leapfrog list starts 6, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 6.Leapfrog list (each number is the sum of the two before it): 2, 8, 10, 18, 28, 46, 74, 120, 194, 314. What is 11 × the 7th number?
- 7.A leapfrog list starts 9, 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, 5, 7, 12, 19, 31, 50, 81, 131, 212. What is 11 × the 7th number?
- 9.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?
- 10.8 + 6 + 14 + 20 + 34 + 54 + 88 + 142 + 230 + 372 =
- 11.8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 + 474 =
- 12.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?
- 13.8 + 5 + 13 + 18 + 31 + 49 + 80 + 129 + 209 + 338 =
- 14.A leapfrog list starts 8, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 15.2 + 1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 =
- 16.Leapfrog list (each number is the sum of the two before it): 8, 5, 13, 18, 31, 49, 80, 129, 209, 338. What is 11 × the 7th number?
- 17.5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 + 309 =
- 18.6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 + 267 + 432 =
- 19.4 + 4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 =
- 20.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?
- 21.3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 + 199 =
- 22.6 + 1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 =
- 23.Leapfrog list (each number is the sum of the two before it): 3, 8, 11, 19, 30, 49, 79, 128, 207, 335. What is 11 × the 7th number?
- 24.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?
- 25.4 + 2 + 6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 =
- 26.4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 + 254 =
- 27.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?
- 28.3 + 2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 =
- 29.A leapfrog list starts 4, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 30.9 + 5 + 14 + 19 + 33 + 52 + 85 + 137 + 222 + 359 =
- 31.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?
- 32.5 + 2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 =
- 33.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?
- 34.Leapfrog list (each number is the sum of the two before it): 4, 3, 7, 10, 17, 27, 44, 71, 115, 186. What is 11 × the 7th number?
- 35.1 + 1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 =
- 36.7 + 7 + 14 + 21 + 35 + 56 + 91 + 147 + 238 + 385 =
- 37.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?
- 38.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?
- 39.3 + 7 + 10 + 17 + 27 + 44 + 71 + 115 + 186 + 301 =
- 40.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?
Answer key
- 1056
- 1177
- 1034
- 1067
- 858
- 814
- 847
- 550
- 319
- 968
- 1232
- 528
- 880
- 528
- 198
- 880
- 803
- 1122
- 572
- 891
- 517
- 418
- 869
- 286
- 396
- 660
- 902
- 341
- 836
- 935
- 682
- 451
- 616
- 484
- 143
- 1001
- 1012
- 1089
- 781
- 1001
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