How big is the bird?

A deceptive brain teaser about profit sharing.

This puzzle is apparently used in job interviews — would you pass?

Number the dots so that each line of three adds up to 22.

Be the first to mark the corners of a square to win this game!

Here's one of our favourite strategy games.

Stretch your mind with this mess-free egg puzzle.

A logic teaser in honour of George Boole.

Exploring the five different notions of average.

Making a biased coin fair.

In how many ways can you make it up the stairs?

Making a very special number out of primes.