Calcudoku

1. 1Fill the grid so that every row and every column holds the digits 1 to the grid size exactly once. There are no boxes and no given digits: the cages tell you everything.
2. 2The corner of each thick-lined cage shows a target and an operation. Its digits add (+), multiply (x), subtract (-) or divide (/) to the target. A cage of one square just holds its number.
3. 3A digit may repeat inside a cage when its squares are not in the same row or column (an L-shaped cage of three can hold 2, 2, 3).
4. 4Work out which digits can make a target: 3+ in two squares is 1 and 2; 2/ in two squares is 1 and 2, 2 and 4, or 3 and 6. The Cage options button lists the sets for the cage you select: it is free, it explains, it never fills a square.
5. 5Check my work marks the digits that are wrong. A hint fills in one square: it costs a little XP, never time.
6. 6There is a new puzzle every day, the same for everyone: a small grid from Sunday to Tuesday, a 5 by 5 from Wednesday to Friday, a 6 by 6 on Saturday. Every puzzle has one solution, found by logic alone.

Keyboard: arrows to move, 1 to 6 to write, N for notes, C for the cage options, Backspace to erase, U to undo.