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 + 5 + 10 + 15 + 25 + 40 + 65 + 105 + 170 + 275 =
- 2.2 + 8 + 10 + 18 + 28 + 46 + 74 + 120 + 194 + 314 =
- 3.A leapfrog list starts 7, 2 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 4.9 + 1 + 10 + 11 + 21 + 32 + 53 + 85 + 138 + 223 =
- 5.5 + 1 + 6 + 7 + 13 + 20 + 33 + 53 + 86 + 139 =
- 6.Leapfrog list (each number is the sum of the two before it): 2, 4, 6, 10, 16, 26, 42, 68, 110, 178. What is 11 × the 7th number?
- 7.2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 =
- 8.Leapfrog list (each number is the sum of the two before it): 6, 1, 7, 8, 15, 23, 38, 61, 99, 160. What is 11 × the 7th number?
- 9.2 + 3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 =
- 10.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?
- 11.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?
- 12.2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 + 348 =
- 13.1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 + 157 =
- 14.Leapfrog list (each number is the sum of the two before it): 4, 1, 5, 6, 11, 17, 28, 45, 73, 118. What is 11 × the 7th number?
- 15.A leapfrog list starts 6, 5 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 16.A leapfrog list starts 2, 7 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): 2, 5, 7, 12, 19, 31, 50, 81, 131, 212. What is 11 × the 7th number?
- 18.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?
- 19.Leapfrog list (each number is the sum of the two before it): 8, 9, 17, 26, 43, 69, 112, 181, 293, 474. What is 11 × the 7th number?
- 20.A leapfrog list starts 5, 3 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 21.3 + 5 + 8 + 13 + 21 + 34 + 55 + 89 + 144 + 233 =
- 22.3 + 1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97 =
- 23.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?
- 24.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?
- 25.7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 + 259 + 419 =
- 26.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?
- 27.A leapfrog list starts 2, 4 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 28.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?
- 29.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?
- 30.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?
- 31.8 + 8 + 16 + 24 + 40 + 64 + 104 + 168 + 272 + 440 =
- 32.3 + 2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 =
- 33.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?
- 34.7 + 2 + 9 + 11 + 20 + 31 + 51 + 82 + 133 + 215 =
- 35.A leapfrog list starts 5, 8 and each next number is the sum of the two before it. What do the first 10 numbers add up to?
- 36.3 + 4 + 7 + 11 + 18 + 29 + 47 + 76 + 123 + 199 =
- 37.4 + 2 + 6 + 8 + 14 + 22 + 36 + 58 + 94 + 152 =
- 38.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?
- 39.1 + 7 + 8 + 15 + 23 + 38 + 61 + 99 + 160 + 259 =
- 40.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?
Answer key
- 715
- 814
- 561
- 583
- 363
- 462
- 550
- 418
- 374
- 737
- 1111
- 902
- 407
- 308
- 770
- 726
- 550
- 891
- 1232
- 539
- 605
- 253
- 847
- 957
- 1089
- 715
- 462
- 1177
- 1067
- 880
- 1144
- 341
- 1144
- 561
- 979
- 517
- 396
- 528
- 671
- 946
Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks