Crossword Mysteries and Sudoku Puzzles

Doing the crossword has long been a Sunday morning ritual, alongside breakfast and the latest news. Crosswords are popular, but sudoku, the number-based logic puzzle, has been waiting for anyone brave enough to try it. The rules are simple: fill the empty squares with the numbers 1 to 9 so that no number is repeated in any row, column or 3 x 3 box. Sounds easy, right? Yet some people never attempt it, either for fear of failure or because they believe they are bad at maths. The good news is that sudoku needs no arithmetic at all, only logic.

How to solve sudoku

Sudoku follows strict rules, which means there are methods that help. If you are just starting, these will get your head in the game.

First, understand the layout. A standard sudoku is a square grid made up of nine large boxes, each containing nine small squares that must hold the numbers 1 to 9. The harder the puzzle, the fewer squares are filled in at the start. The large boxes have a thick outline and the small squares a thin one. The basic rule to remember is that every row, every column and every box must contain all the numbers from 1 to 9.

Next, use the clues you are given. Pick a number and look at where it already appears. If a 5 is already in a row, no other square in that row can be a 5; the same goes for its column and box. Scanning across and down like this often leaves only one possible square for a number in a box.

You can also work the other way round: look at a single empty square and list which numbers could still go there. If only one number is possible, write it in.

Another method is to work in number groups. Take one number at a time, see everywhere it has been placed on the board and check whether you can place any more of it. Many solvers write small pencil notes in the corner of squares to track possible candidates.

Important tips for sudoku and crosswords

Whether you are filling in a crossword or a sudoku, use a pencil rather than a pen. Crossword mysteries can be confusing, and it is easy to make mistakes. A pen leaves the grid messy and makes changing answers difficult.

Do not be afraid to leave a puzzle and come back later. A fresh look often reveals the answer you missed. For more on the different number and word puzzles out there, see our guide to puzzle types.