Fill the grid so every row, every column and every 3 × 3 box holds the digits 1–9, each exactly once.

The dashed outlines are cages: the digits in a cage add up to the small number in its corner, and no digit repeats within a cage.

No digit is given. The sums are enough: there is exactly one solution, and it never needs a guess.

Tap a cell and pick a digit on the pad under the board; the same digit again clears it. With notes on, digits are pencilled small in the cell instead. Under the pad: the selected cage’s combinations, and a calculator for adding up sums.

A reddish cell holds a digit its row, column, box or cage already has, or sits in a cage whose sum has gone wrong; a cage’s sum and outline grey out once it is done.

Learn the solving techniques