Look the Boxes first:
It’s easier to solve the sudoku game by looking at the boxes first as they are normally easier to solve. Look at the top 3 boxes of the sudoku table (the sudoku table contains 9 boxes and 81 cells), which have the top three rows running through them, and see if there’s a number that appears in two of the boxes but not in the third one. Because that number has to appear somewhere in the third block, the choice is limited to only three cells at most, because that number can’t appear in the two rows that already contain the number. If any of the three cells in question are already occupied with numbers, our possible answer may narrow down to one or two cells. If it is narrowed down to one cell, that is your solution – that is where you should plug in the number, but if you still have two or three possibilities, you should look at the columns running through this box and try to determine if you can narrow down your options to only one. You can repeat the process above for every 3 sudoku boxes, vertical or horizontal, using the same suoku logic.

If you’re new to sudoku, you should go through the step by step solution for the easy level sudoku.  Will need to look at the 2 boxes below and look at the columns that run through them.

Look the row and columns then:

Pick a column or a row that is close to being completed and start close checking. If a cell has a few possible answers, skip it and try to find one cell that has only one answer. While you cross checking, always remember the sudoku general rules: Each row or column must contain the number 1 through 9. Therefore, no number can be repeated twice in a row or a column – knowing where numbers can’t go is just as important as knowing where they can go.