When teaching children about physical maps, I begin with drawing a simple plan of the classroom on the blackboard and then on a worksheet, including cupboards, blackboard, desks, chairs etc.

The children have to colour the plan using the colours from a physical map i.e. green for floor level, yellow for mid level (desks, chairs etc.) brown for the highest objects in the room.

Then when you begin to study physical maps, the children have an understanding of the colours used.