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 8, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 2.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?
- 3.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?
- 4.8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 + 474 =
- 5.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?
- 6.3 + 2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 =
- 7.Leapfrog list (each number is the sum of the two before it): 7, 4, 11, 15, 26, 41, 67, 108, 175, 283. What is 11 × the 7th number?
- 8.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?
- 9.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?
- 10.Leapfrog list (each number is the sum of the two before it): 1, 2, 3, 5, 8, 13, 21, 34, 55, 89. What is 11 × the 7th number?
- 11.7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 + 259 + 419 =
- 12.9 + 5 + 14 + 19 + 33 + 52 + 85 + 137 + 222 + 359 =
- 13.5 + 2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 =
- 14.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?
- 15.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?
- 16.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?
- 17.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?
- 18.3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 + 199 =
- 19.Leapfrog list (each number is the sum of the two before it): 1, 5, 6, 11, 17, 28, 45, 73, 118, 191. What is 11 × the 7th number?
- 20.2 + 4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 + 178 =
- 21.9 + 7 + 16 + 23 + 39 + 62 + 101 + 163 + 264 + 427 =
- 22.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?
- 23.3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 + 369 =
- 24.9 + 1 + 10 + 11 + 21 + 32 + 53 + 85 + 138 + 223 =
- 25.Leapfrog list (each number is the sum of the two before it): 5, 7, 12, 19, 31, 50, 81, 131, 212, 343. What is 11 × the 7th number?
- 26.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?
- 27.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?
- 28.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?
- 29.8 + 8 + 16 + 24 + 40 + 64 + 104 + 168 + 272 + 440 =
- 30.6 + 4 + 10 + 14 + 24 + 38 + 62 + 100 + 162 + 262 =
- 31.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?
- 32.Leapfrog list (each number is the sum of the two before it): 3, 2, 5, 7, 12, 19, 31, 50, 81, 131. What is 11 × the 7th number?
- 33.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?
- 34.A leapfrog list starts 4, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 35.1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 =
- 36.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?
- 37.Leapfrog list (each number is the sum of the two before it): 3, 1, 4, 5, 9, 14, 23, 37, 60, 97. What is 11 × the 7th number?
- 38.Leapfrog list (each number is the sum of the two before it): 9, 7, 16, 23, 39, 62, 101, 163, 264, 427. What is 11 × the 7th number?
- 39.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?
- 40.9 + 2 + 11 + 13 + 24 + 37 + 61 + 98 + 159 + 257 =
Answer key
- 1144
- 1023
- 869
- 1232
- 814
- 341
- 737
- 638
- 429
- 231
- 1089
- 935
- 451
- 473
- 847
- 572
- 1144
- 517
- 495
- 462
- 1111
- 946
- 957
- 583
- 891
- 803
- 682
- 1034
- 1144
- 682
- 528
- 341
- 891
- 308
- 231
- 715
- 253
- 1111
- 506
- 671
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