well actually, no, soduko starts with 3 to 6 numbers missing on each box so example, this is how soduko starts, to finish, you will have to fill in all boxes so that they contain 1-9 in each column, row, and boxes.
--2 -9- 5--
3-- --- --2
57- -21 -83
--1 6-- -2-
--- -3- ---
-2- --4 9--...