The key to improving concentration isn't powering through Sudoku puzzles without stopping. Taking short breaks between ...

Welcome to our free impossible sudoku games. Fill in each square with a number, making sure no number repeats in each column or row. Check back every Sunday for a new puzzle or explore ones we ...

All four cells have the same two candidates left (in real Sudoku, not all cells have to hold all of the UR candidates)." ...

Play our daily hard sudoku here. Plus, you can let us know what you think of the puzzles by emailing at hey@metro.co.uk. We look forward to hearing from you.

The World Sudoku Championships start on Monday, with competitors from 31 countries set to spend 28 hours solving the toughest ...

Play our daily hard sudoku here. Plus, you can let us know what you think of the puzzles by emailing at hey@metro.co.uk. We look forward to hearing from you.

As always, we're serving up our daily hints and tips to help you figure out today's answer. If you just want to be told today ...

Known as the “Godfather of Sudoku,” Kaji created the puzzle to be easy for children and others who didn’t want to think too hard. Its name is made up of the Japanese characters for “number ...

In a typical four-year term, a president replaces about one-quarter of the country’s 870 active federal judges, across both ...

(1) A part of a program that has been declared as unchanging. For example, a constant is hard coded and remains the same throughout the execution of the program. (2) Programming code that solves a ...

But even as every doctor we see continues to give us the thumbs-up, I’m finding it hard to comprehend. Like Charlie Brown ...

Get all three sports-related questions of varying difficulty (easy, medium and hard) and you claim the Herald hat-trick. Want more quizzes? Test your knowledge in the Herald’s Morning quiz and ...