Puzzler Kakuro

1. Pick Easy, Medium or Hard to start a puzzle.
2. Each clue gives the total of the run of cells to its right (across) or below it (down).
3. Fill the white cells with digits 1 to 9 so every run adds up to its clue.
4. Never repeat a digit inside the same run; a digit can repeat elsewhere in the grid.
5. Start with sums that can only be made one way, such as 3 in two cells (1 + 2).

Kakuro is a crossword made of numbers. Instead of words, each white run of cells has a clue telling you what its digits must add up to, and you fill it with the digits 1 to 9, never using the same digit twice in one run. Every cell belongs to one run across and one run down, so each digit has to satisfy two sums at once, and that crossing is where the logic happens. Puzzler Kakuro gives you a fresh grid at three levels, Easy, Medium and Hard, and plays in the browser on a computer, tablet or phone, held either way. It is the puzzle for anyone who likes sudoku but wants arithmetic in it too: small sums like 3 or 4 in two cells can only be made one way, and spotting those is how every grid starts to open up.