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
- 1.5 + 1 + 6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 =
- 2.6 + 4 + 10 + 14 + 24 + 38 + 62 + 100 + 162 + 262 =
- 3.6 + 2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 =
- 4.Leapfrog list (each number is the sum of the two before it): 9, 3, 12, 15, 27, 42, 69, 111, 180, 291. What is 11 × the 7th number?
- 5.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?
- 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.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?
- 8.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?
- 9.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?
- 10.3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 + 369 =
- 11.Leapfrog list (each number is the sum of the two before it): 5, 4, 9, 13, 22, 35, 57, 92, 149, 241. What is 11 × the 7th number?
- 12.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?
- 13.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?
- 14.9 + 4 + 13 + 17 + 30 + 47 + 77 + 124 + 201 + 325 =
- 15.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?
- 16.Leapfrog list (each number is the sum of the two before it): 2, 3, 5, 8, 13, 21, 34, 55, 89, 144. What is 11 × the 7th number?
- 17.Leapfrog list (each number is the sum of the two before it): 9, 6, 15, 21, 36, 57, 93, 150, 243, 393. What is 11 × the 7th number?
- 18.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?
- 19.2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 + 348 =
- 20.A leapfrog list starts 5, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 21.2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 + 178 =
- 22.A leapfrog list starts 2, 5 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): 6, 3, 9, 12, 21, 33, 54, 87, 141, 228. What is 11 × the 7th number?
- 24.A leapfrog list starts 2, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 25.Leapfrog list (each number is the sum of the two before it): 4, 2, 6, 8, 14, 22, 36, 58, 94, 152. What is 11 × the 7th number?
- 26.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?
- 27.5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 + 343 =
- 28.A leapfrog list starts 4, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 29.5 + 5 + 10 + 15 + 25 + 40 + 65 + 105 + 170 + 275 =
- 30.Leapfrog list (each number is the sum of the two before it): 2, 7, 9, 16, 25, 41, 66, 107, 173, 280. What is 11 × the 7th number?
- 31.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?
- 32.8 + 6 + 14 + 20 + 34 + 54 + 88 + 142 + 230 + 372 =
- 33.Leapfrog list (each number is the sum of the two before it): 4, 1, 5, 6, 11, 17, 28, 45, 73, 118. What is 11 × the 7th number?
- 34.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?
- 35.4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 + 178 + 288 =
- 36.6 + 6 + 12 + 18 + 30 + 48 + 78 + 126 + 204 + 330 =
- 37.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?
- 38.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?
- 39.9 + 5 + 14 + 19 + 33 + 52 + 85 + 137 + 222 + 359 =
- 40.4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 + 254 =
Answer key
- 363
- 682
- 506
- 759
- 649
- 363
- 858
- 770
- 814
- 957
- 627
- 473
- 407
- 847
- 143
- 374
- 1023
- 836
- 902
- 627
- 462
- 550
- 594
- 374
- 396
- 572
- 891
- 484
- 715
- 726
- 451
- 968
- 308
- 319
- 748
- 858
- 847
- 319
- 935
- 660
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