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): 3, 2, 5, 7, 12, 19, 31, 50, 81, 131. What is 11 × the 7th number?
- 2.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?
- 3.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?
- 4.7 + 3 + 10 + 13 + 23 + 36 + 59 + 95 + 154 + 249 =
- 5.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?
- 6.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?
- 7.6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 + 246 + 398 =
- 8.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?
- 9.2 + 1 + 3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 =
- 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?
- 11.9 + 5 + 14 + 19 + 33 + 52 + 85 + 137 + 222 + 359 =
- 12.7 + 4 + 11 + 15 + 26 + 41 + 67 + 108 + 175 + 283 =
- 13.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?
- 14.4 + 1 + 5 + 6 + 11 + 17 + 28 + 45 + 73 + 118 =
- 15.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?
- 16.5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 + 254 + 411 =
- 17.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?
- 18.1 + 9 + 10 + 19 + 29 + 48 + 77 + 125 + 202 + 327 =
- 19.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?
- 20.1 + 1 + 2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 =
- 21.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?
- 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.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?
- 24.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?
- 25.2 + 7 + 9 + 16 + 25 + 41 + 66 + 107 + 173 + 280 =
- 26.4 + 9 + 13 + 22 + 35 + 57 + 92 + 149 + 241 + 390 =
- 27.Leapfrog list (each number is the sum of the two before it): 7, 2, 9, 11, 20, 31, 51, 82, 133, 215. What is 11 × the 7th number?
- 28.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?
- 29.A leapfrog list starts 1, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 30.3 + 7 + 10 + 17 + 27 + 44 + 71 + 115 + 186 + 301 =
- 31.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?
- 32.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?
- 33.6 + 2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 =
- 34.A leapfrog list starts 9, 1 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 35.Leapfrog list (each number is the sum of the two before it): 2, 2, 4, 6, 10, 16, 26, 42, 68, 110. What is 11 × the 7th number?
- 36.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?
- 37.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?
- 38.Leapfrog list (each number is the sum of the two before it): 4, 3, 7, 10, 17, 27, 44, 71, 115, 186. What is 11 × the 7th number?
- 39.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?
- 40.5 + 3 + 8 + 11 + 19 + 30 + 49 + 79 + 128 + 207 =
Answer key
- 341
- 528
- 308
- 649
- 231
- 319
- 1034
- 858
- 198
- 253
- 935
- 737
- 143
- 308
- 231
- 1067
- 583
- 847
- 605
- 143
- 286
- 1034
- 737
- 902
- 726
- 1012
- 561
- 429
- 495
- 781
- 605
- 550
- 506
- 583
- 286
- 715
- 506
- 484
- 759
- 539
Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks