Fill in the grid so that every row, every column, and every 3 x 3 box contains the digits 1 through 9. Additional the rows form 9 correct arithmetic expressions reading from left to right.
There is only one solution. You can find it by logic.
Unfortunatly there would be no additional equalities and then it looks not so nice for me. I guess that a smaller number of givens is possible but I haven't such a puzzle made yet.