Your bathroom is the perfect place to think about the concept of capacity in maths. In EYFS we explore simple capacity terms such as full, half full, nearly full and empty. You could get lots of different containers in the bath and have fun exploring!
Lots of people have mirrors in their bathrooms to help get washed and ready. Mirrors can also be used in maths to explore doubles. Place some objects in front of the mirror and watch as their reflections make them double!