Why do you think that the red player chose that particular dot in this game of Seeing Squares?

Seeing Squares game for an adult and child. Can you come up with a way of always winning this game?

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.

What is the greatest number of squares you can make by overlapping three squares?

What shape has Harry drawn on this clock face? Can you find its area? What is the largest number of square tiles that could cover this area?

A tilted square is a square with no horizontal sides. Can you devise a general instruction for the construction of a square when you are given just one of its sides?

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.

What is the total area of the four outside triangles which are outlined in red in this arrangement of squares inside each other?

On the graph there are 28 marked points. These points all mark the vertices (corners) of eight hidden squares. Can you find the eight hidden squares?

ABCD is a regular tetrahedron and the points P, Q, R and S are the midpoints of the edges AB, BD, CD and CA. Prove that PQRS is a square.

What is the minimum number of squares a 13 by 13 square can be dissected into?

These points all mark the vertices (corners) of ten hidden squares. Can you find the 10 hidden 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?

The whole set of tiles is used to make a square. This has a green and blue border. There are no green or blue tiles anywhere in the square except on this border. How many tiles are there in the set?

Just four procedures were used to produce a design. How was it done? Can you be systematic and elegant so that someone can follow your logic?

What can you see? What do you notice? What questions can you ask?

If you move the tiles around, can you make squares with different coloured edges?

A 2 by 3 rectangle contains 8 squares and a 3 by 4 rectangle contains 20 squares. What size rectangle(s) contain(s) exactly 100 squares? Can you find them all?

Start with a large square, join the midpoints of its sides, you'll see four right angled triangles. Remove these triangles, a second square is left. Repeat the operation. What happens?

How many ways can you find of tiling the square patio, using square tiles of different sizes?

This article for teachers suggests activities based on pegboards, from pattern generation to finding all possible triangles, for example.

Can you dissect a square into: 4, 7, 10, 13... other squares? 6, 9, 12, 15... other squares? 8, 11, 14... other squares?

This practical challenge invites you to investigate the different squares you can make on a square geoboard or pegboard.

Investigate all the different squares you can make on this 5 by 5 grid by making your starting side go from the bottom left hand point. Can you find out the areas of all these squares?

How many centimetres of rope will I need to make another mat just like the one I have here?

What is the smallest number of tiles needed to tile this patio? Can you investigate patios of different sizes?

Can you each work out what shape you have part of on your card? What will the rest of it look like?

Investigate how this pattern of squares continues. You could measure lengths, areas and angles.

These rectangles have been torn. How many squares did each one have inside it before it was ripped?

Look at how the pattern is built up - in that way you will know how to break the final pattern down into more manageable pieces.

Cut a square of paper into three pieces as shown. Now,can you use the 3 pieces to make a large triangle, a parallelogram and the square again?

This problem challenges you to work out what fraction of the whole area of these pictures is taken up by various shapes.

Have a good look at these images. Can you describe what is happening? There are plenty more images like this on NRICH's Exploring Squares CD.

How would you move the bands on the pegboard to alter these shapes?

This activity investigates how you might make squares and pentominoes from Polydron.

Can you find the squares hidden on these coordinate grids?

Nine squares with side lengths 1, 4, 7, 8, 9, 10, 14, 15, and 18 cm can be fitted together to form a rectangle. What are the dimensions of the rectangle?

This interactivity allows you to sort logic blocks by dragging their images.

With one cut a piece of card 16 cm by 9 cm can be made into two pieces which can be rearranged to form a square 12 cm by 12 cm. Explain how this can be done.

Creating designs with squares - using the REPEAT command in LOGO. This requires some careful thought on angles

Can you work out the area of the inner square and give an explanation of how you did it?

Can you use LOGO to create a systematic reproduction of a basic design? An introduction to variables in a familiar setting.

This LOGO Challenge emphasises the idea of breaking down a problem into smaller manageable parts. Working on squares and angles.

A Short introduction to using Logo. This is the first in a twelve part series.

What fraction of this square is shaded?

Can you recreate squares and rhombuses if you are only given a side or a diagonal?

Using LOGO, can you construct elegant procedures that will draw this family of 'floor coverings'?