## 'Squares in Rectangles' printed from http://nrich.maths.org/

A $2$ by $3$ rectangle contains $8$ squares. Can you see how?

A $3$ by $4$ rectangle contains $20$ squares. Can you see how?

A $4$ by $6$ rectangle contains $50$ squares. Can you see how?

What size rectangle contains exactly $100$ squares?

Is there more than one?
Can you find them all?
Can you prove that there are no more?

Click here for a poster of this problem.