Kakuro
Rules
1. Put a number from 1 through 9 in a cell (No zeros).
2. A number in a cell separated by diagonal line tells the sum of numbers in consecutive
cells at its right or downward.
3. No number may appear more than once in consecutive cells.
Features
This puzzle was first introduced in Puzzle magazine Nikoli Vol.11 and since then it has gained enormous popularity from wide group of people and now is the king of pencil puzzles. The more you solve, the better you become at Kakuro and your hand moves so fast chasing the answer numbers flashing in your head even without thinking. It is inexpressible enjoyment.Don't worry about addition and subtraction, because Nikoli's Kakuro keeps those parts as less as possible.
When you feel like starting Kakuro, just use the fixed patterns. You'll see them work and your first Kakuro is finished.