Here's a game to play with an adult!
How do you play?
You'll need an adult to play with.
You'll also need a set of blank grids, or you could use the tablet-friendly Seeing Squares interactivity.
Choose a different colour for you and the adult, and take it in turns to draw a dot on the grid - the player who is drawing the blue dots will go first. The winner is the first to have four dots that can be joined by straight lines to form a square. Squares can be any size, anywhere and can be tilted.
Can you work out a strategy? Justify why you think each move is a good one.
How do you know when you've made a square?