This is a list of resources for interpreting different types of charts and diagrams. It is suitable for levels 3-5. The list can be used in the order given. I would suggest it would take no more than 2 lessons to teach. The final resource can be extended, it would depend on how much data gathering you want to do from the website and whether you had the data pre-prepared or took pupils into a computer room to allow them to gather their own data.