If you mean sudoku, first off forget about math.
You do not even need to be able to count or add 2+2 to play sudoku. The numbers only represent symbols that could just as well be letters.
The basic idea is that the same number is never used
twice in any row (across), column (up/down) or in the same box (one of the three by three cubicles). If you carefully examine a sudoku puzzle in any degree of completion you will see that this is so.
To do the puzzle you find, mostly by elimination, the correct number that goes in each space to complete the grid. Do not enter a guess until you are certain it is the only number that belongs. Look at different spaces until you find one for which the number that belongs there can be determined. Putting the wrong number in a space will make it impossible to complete the grid.
Try some easy puzzles until you thoroughly grasp the concept and gain confidence to take on a more challenging puzzle.
Start here!