Rules and execise of Sudoku

Sudoku has more rules than other puzzles, but popular from beginners to experts.

Rules of Sudoku

  1. Place a number (1-9) in each blank cell.
  2. Each row (nine lines from left to right), column (also nine lines from top to bottom) and 3x3 block bounded by bold line (nine blocks) contains number from 1 through 9.
01

Sample

07

Solution



Sudoku exercise

01

Check where numbers can go to get started, so first look at the rows and columns.


02

For the top 3x3 blocks there is a 1 in the middle and right blocks, so there is only one place where the 1 can go in left block.


03

In this figure there is also only one place where the 1 can go.


04

Did you follow so far? The trick is to look everywhere in the Sudoku square and you will simply find where a number has to go.


05

Each row and block has to contain the numbers 1 to 9.


06

Here is a little tip for advanced folks. Can you see where the 1 can go here?


07

There are two cells that may get a 1 in the top left 3x3 block, both in the same row!


08

So, in this figure, you can't put the 1 into the yellow cells.


09

Here 1 has to go in right next to the 6. We still don't know which of the two orange cells will get the 1, but we can specify the top middle cell where 1 has to go into.


09

There are many more tips. Good luck finding your own as you go along.