How to play Calcudoku

Sudoku with arithmetic: fill the grid so no digit repeats, and every cage reaches its target.

The rules, step by step

Fill the grid with the digits from 1 up to the size of the grid, so each digit appears once in every row and every column.
The thick outlines mark cages. The small label in the corner of a cage gives its target and operation.
A label such as 7+ means the digits add to 7, 12× means they multiply to 12, 3− means they differ by 3, and 2÷ means one is twice the other.
A cage with only a number is a single square: that is the digit.
Unlike Sudoku, a digit can repeat inside a cage if its squares are in different rows and columns.

Fill any single-square cages first. Then look at two-square cages with an unusual target: in a 4x4 grid, 12× can only be 3 and 4.

Think about which pairs of digits can make the target, then use the rows and columns to choose.
Large products and small sums have few possibilities, so they are good places to start.
Press Check to find squares that break a rule.