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 + 8 + 13 + 21 + 34 + 55 + 89 + 144 + 233 + 377 =
- 2.5 + 4 + 9 + 13 + 22 + 35 + 57 + 92 + 149 + 241 =
- 3.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?
- 4.Leapfrog list (each number is the sum of the two before it): 3, 5, 8, 13, 21, 34, 55, 89, 144, 233. What is 11 × the 7th number?
- 5.3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 + 199 =
- 6.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?
- 7.A leapfrog list starts 9, 3 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): 8, 6, 14, 20, 34, 54, 88, 142, 230, 372. What is 11 × the 7th number?
- 9.9 + 8 + 17 + 25 + 42 + 67 + 109 + 176 + 285 + 461 =
- 10.4 + 3 + 7 + 10 + 17 + 27 + 44 + 71 + 115 + 186 =
- 11.4 + 9 + 13 + 22 + 35 + 57 + 92 + 149 + 241 + 390 =
- 12.A leapfrog list starts 6, 2 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 8, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 14.Leapfrog list (each number is the sum of the two before it): 9, 9, 18, 27, 45, 72, 117, 189, 306, 495. What is 11 × the 7th number?
- 15.5 + 5 + 10 + 15 + 25 + 40 + 65 + 105 + 170 + 275 =
- 16.A leapfrog list starts 3, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 17.Leapfrog list (each number is the sum of the two before it): 3, 9, 12, 21, 33, 54, 87, 141, 228, 369. What is 11 × the 7th number?
- 18.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?
- 19.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?
- 20.6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 + 225 + 364 =
- 21.7 + 7 + 14 + 21 + 35 + 56 + 91 + 147 + 238 + 385 =
- 22.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?
- 23.A leapfrog list starts 5, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 24.A leapfrog list starts 8, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 25.2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 =
- 26.Leapfrog list (each number is the sum of the two before it): 9, 4, 13, 17, 30, 47, 77, 124, 201, 325. What is 11 × the 7th number?
- 27.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?
- 28.Leapfrog list (each number is the sum of the two before it): 2, 1, 3, 4, 7, 11, 18, 29, 47, 76. What is 11 × the 7th number?
- 29.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?
- 30.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?
- 31.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?
- 32.8 + 9 + 17 + 26 + 43 + 69 + 112 + 181 + 293 + 474 =
- 33.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?
- 34.6 + 4 + 10 + 14 + 24 + 38 + 62 + 100 + 162 + 262 =
- 35.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?
- 36.3 + 8 + 11 + 19 + 30 + 49 + 79 + 128 + 207 + 335 =
- 37.9 + 6 + 15 + 21 + 36 + 57 + 93 + 150 + 243 + 393 =
- 38.3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 + 369 =
- 39.6 + 1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 =
- 40.A leapfrog list starts 1, 7 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
Answer key
- 979
- 627
- 528
- 605
- 517
- 143
- 759
- 968
- 1199
- 484
- 1012
- 506
- 968
- 1287
- 715
- 957
- 957
- 495
- 1034
- 946
- 1001
- 836
- 715
- 880
- 550
- 847
- 583
- 198
- 253
- 198
- 506
- 1232
- 396
- 682
- 836
- 869
- 1023
- 957
- 418
- 671
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