Size of standard blackboard

The height should not be less than 1000 mm. The standard blackboard size is: height not less than 1000mm, width not less than 3600mm in primary school and not less than 4000mm in middle school. The vertical distance between the lower edge of the blackboard and the platform: 800-900 mm; For primary schools; Middle school should be1000-1100 mm blackboard. Traditionally, it is a plane that can be written repeatedly with chalk. The board is relatively hard and is mostly used for teaching.