A Sudoku puzzle is defined as a logic-based, number-placement puzzle. The objective is to fill a 9×9 grid with digits in such a way that each column, each row, and each of the nine 3×3 grids that make up the larger 9×9 grid contains all of the digits from 1 to 9.

When playing with pen/pencil & paper, people put marks on the sudoku grid to assist them in remembering where numbers can possibly be placed before determining the correct value of the box.

This Sudoku Pencil Mark helper is a web-based Sudoku grid to assist players in recording the test, and real / actual numbers to go in each box.