Practice

How practice differs

Boards here are drawn at random rather than from the date. They do not count towards your streak, they are not shareable, and you can take as many as you like.

Easy boards have nine lines and use the mistakes you can spot by eye. Hard boards have seventeen lines and are built to mislead: when the answer is not a digit error, the difference is still arranged to divide by 9, so the first thing you reach for is wrong.

For the one that counts, go back to today's puzzle.