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, 9, 15, 24, 39, 63, 102, 165, 267, 432. What is 11 × the 7th number?
- 2.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?
- 3.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?
- 4.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?
- 5.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?
- 6.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?
- 7.A leapfrog list starts 8, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 8.2 + 1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 =
- 9.6 + 1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 =
- 10.Leapfrog list (each number is the sum of the two before it): 9, 5, 14, 19, 33, 52, 85, 137, 222, 359. What is 11 × the 7th number?
- 11.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?
- 12.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?
- 13.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?
- 14.4 + 4 + 8 + 12 + 20 + 32 + 52 + 84 + 136 + 220 =
- 15.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?
- 16.Leapfrog list (each number is the sum of the two before it): 8, 8, 16, 24, 40, 64, 104, 168, 272, 440. What is 11 × the 7th number?
- 17.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?
- 18.9 + 6 + 15 + 21 + 36 + 57 + 93 + 150 + 243 + 393 =
- 19.A leapfrog list starts 7, 3 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): 3, 3, 6, 9, 15, 24, 39, 63, 102, 165. What is 11 × the 7th number?
- 21.Leapfrog list (each number is the sum of the two before it): 8, 2, 10, 12, 22, 34, 56, 90, 146, 236. What is 11 × the 7th number?
- 22.1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 =
- 23.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?
- 24.5 + 5 + 10 + 15 + 25 + 40 + 65 + 105 + 170 + 275 =
- 25.A leapfrog list starts 3, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 26.A leapfrog list starts 6, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 27.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?
- 28.Leapfrog list (each number is the sum of the two before it): 3, 6, 9, 15, 24, 39, 63, 102, 165, 267. What is 11 × the 7th number?
- 29.8 + 7 + 15 + 22 + 37 + 59 + 96 + 155 + 251 + 406 =
- 30.A leapfrog list starts 1, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 31.5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 + 233 + 377 =
- 32.A leapfrog list starts 9, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 33.4 + 3 + 7 + 10 + 17 + 27 + 44 + 71 + 115 + 186 =
- 34.9 + 9 + 18 + 27 + 45 + 72 + 117 + 189 + 306 + 495 =
- 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.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?
- 38.7 + 2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 =
- 39.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?
- 40.9 + 5 + 14 + 19 + 33 + 52 + 85 + 137 + 222 + 359 =
Answer key
- 1122
- 847
- 902
- 616
- 572
- 902
- 1144
- 198
- 418
- 935
- 550
- 858
- 341
- 572
- 1034
- 1144
- 286
- 1023
- 649
- 429
- 616
- 319
- 770
- 715
- 605
- 1034
- 429
- 693
- 1056
- 847
- 979
- 935
- 484
- 1287
- 1089
- 506
- 1001
- 561
- 319
- 935
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