Sara and Will were sorting some pictures of shapes on cards. "I'll collect the circles," said Sara. "I'll take the red ones," answered Will. Can you see any cards they would both want?
Players take it in turns to choose a dot on the grid. The winner is the first to have four dots that can be joined to form a square.
Where can you put the mirror across the square so that you can still "see" the whole square? How many different positions are possible?
This problem challenges you to work out what fraction of the whole area of these pictures is taken up by various shapes.
What is the greatest number of squares you can make by overlapping three squares?
What is the greatest number of counters you can place on the grid below without four of them lying at the corners of a square?
