Rules:
Normal Sudoku rules apply.
Numbers along an arrow sum to the digit in the circle.
The number in the top left corner of each cage represents either the sum, the difference, the product or the quotient (the larger digit divided by the smaller digit) of the two digits in the cage. Filled in cages are allowed to satisfy more than one type of calculation at once, but the solver has to assign each cage exactly one type so that every type of cage appears four times in the grid.
Solution code: Column 3, followed by Row 3.