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, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 2.9 + 3 + 12 + 15 + 27 + 42 + 69 + 111 + 180 + 291 =
- 3.A leapfrog list starts 8, 7 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 1, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 5.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?
- 6.9 + 1 + 10 + 11 + 21 + 32 + 53 + 85 + 138 + 223 =
- 7.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?
- 8.6 + 3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 =
- 9.A leapfrog list starts 4, 5 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): 8, 1, 9, 10, 19, 29, 48, 77, 125, 202. What is 11 × the 7th number?
- 11.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?
- 12.A leapfrog list starts 3, 6 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 13.8 + 5 + 13 + 18 + 31 + 49 + 80 + 129 + 209 + 338 =
- 14.7 + 3 + 10 + 13 + 23 + 36 + 59 + 95 + 154 + 249 =
- 15.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?
- 16.6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 + 225 + 364 =
- 17.6 + 1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 =
- 18.6 + 4 + 10 + 14 + 24 + 38 + 62 + 100 + 162 + 262 =
- 19.1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 + 191 =
- 20.9 + 8 + 17 + 25 + 42 + 67 + 109 + 176 + 285 + 461 =
- 21.1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 + 259 =
- 22.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?
- 23.4 + 6 + 10 + 16 + 26 + 42 + 68 + 110 + 178 + 288 =
- 24.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?
- 25.2 + 6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 =
- 26.A leapfrog list starts 6, 9 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 1, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 28.1 + 1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 =
- 29.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?
- 30.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?
- 31.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?
- 32.2 + 1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 =
- 33.A leapfrog list starts 6, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 34.9 + 4 + 13 + 17 + 30 + 47 + 77 + 124 + 201 + 325 =
- 35.1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 =
- 36.3 + 9 + 12 + 21 + 33 + 54 + 87 + 141 + 228 + 369 =
- 37.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?
- 38.1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 =
- 39.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?
- 40.4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 + 254 =
Answer key
- 704
- 759
- 1056
- 231
- 891
- 583
- 902
- 594
- 660
- 528
- 1034
- 693
- 880
- 649
- 902
- 946
- 418
- 682
- 495
- 1199
- 671
- 583
- 748
- 935
- 638
- 1122
- 319
- 143
- 594
- 1089
- 858
- 198
- 594
- 847
- 231
- 957
- 429
- 407
- 946
- 660
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