What are the advantages of chalk-board over other visual aids?

Advantages of chalk-board over other visual aids are:

(i) It is a very convenient teaching aid for group teaching.

(ii) It is quite economical and can be used again and again.

(iii) Its use is accompanied by the appropriate actions on the part of the teacher. The illustrations drawn on the black board captures student’s attention.

Image source: pfl.grad.ncsu.edu/files/2013/11/Behave-like-a-teacher.jpg

(iv) It is one of the most valuable supplementary teaching aid.

(v) It can be used as a good visual aid for drill and revision.

(vi) These boards can be used for drawing enlarged illus­trations from the text books.

(vii) It is a convenient aid for giving lesson notes to the students.