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
- 1.1 + 1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 =
- 2.5 + 3 + 8 + 11 + 19 + 30 + 49 + 79 + 128 + 207 =
- 3.5 + 4 + 9 + 13 + 22 + 35 + 57 + 92 + 149 + 241 =
- 4.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?
- 5.5 + 5 + 10 + 15 + 25 + 40 + 65 + 105 + 170 + 275 =
- 6.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?
- 7.4 + 1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 =
- 8.6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 + 398 =
- 9.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?
- 10.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?
- 11.6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 + 225 + 364 =
- 12.A leapfrog list starts 8, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 13.2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 =
- 14.4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 + 199 + 322 =
- 15.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?
- 16.Leapfrog list (each number is the sum of the two before it): 8, 4, 12, 16, 28, 44, 72, 116, 188, 304. What is 11 × the 7th number?
- 17.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?
- 18.Leapfrog list (each number is the sum of the two before it): 7, 9, 16, 25, 41, 66, 107, 173, 280, 453. What is 11 × the 7th number?
- 19.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?
- 20.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?
- 21.Leapfrog list (each number is the sum of the two before it): 1, 1, 2, 3, 5, 8, 13, 21, 34, 55. What is 11 × the 7th number?
- 22.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?
- 23.A leapfrog list starts 3, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 24.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?
- 25.5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 + 254 + 411 =
- 26.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?
- 27.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?
- 28.9 + 8 + 17 + 25 + 42 + 67 + 109 + 176 + 285 + 461 =
- 29.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?
- 30.5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 + 343 =
- 31.Leapfrog list (each number is the sum of the two before it): 4, 6, 10, 16, 26, 42, 68, 110, 178, 288. What is 11 × the 7th number?
- 32.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?
- 33.Leapfrog list (each number is the sum of the two before it): 5, 9, 14, 23, 37, 60, 97, 157, 254, 411. What is 11 × the 7th number?
- 34.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?
- 35.1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 + 259 =
- 36.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?
- 37.A leapfrog list starts 9, 9 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 38.2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 =
- 39.3 + 6 + 9 + 15 + 24 + 39 + 63 + 102 + 165 + 267 =
- 40.A leapfrog list starts 7, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
Answer key
- 143
- 539
- 627
- 550
- 715
- 473
- 308
- 1034
- 143
- 253
- 946
- 1232
- 726
- 836
- 1177
- 792
- 726
- 1177
- 374
- 429
- 143
- 1034
- 253
- 528
- 1067
- 869
- 759
- 1199
- 649
- 891
- 748
- 605
- 1067
- 858
- 671
- 594
- 1287
- 374
- 693
- 737
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