Capacity is the amount something can contain. The best way we learn about this in Reception is through water play. Before Reception, children will have had experience of capacity by filling and emptying containers - this can be in the bath, in a sand pit, filling containers with objects, etc. Therefore, children will already be aware of this mathematical concept. They will definitely be able to recognise a full or only half full bag of sweets and which one they would prefer! We must teach them about the language of capacity, including full, empty, half full and nearly empty. How does capacity change? Do we add more or less?