This list is aimed at the lower end of KS3. The resources are suitable for pupils who have not learnt about averages before. I would suggest using the resources in the order I have listed them. The first 2 resources are good for introducing the topic, teaching it, giving examples and the pupils having a go at questions. The third resource does the same but from a functional point of view. The other resources are all interesting cross-curricular functional ideas to do with pupils that show them the relevance of averages. This unit of work could take 3 or more lessons, depending on how many of the cross-curricular resources you choose to use.