a man is teaching
a man is teaching math by using a white board
a man is teaching math
a man is teaching mathematical concepts
a man is writing
a man is writing on a chalkboard about factoring polynomials
a man is writing on a whiteboard
a man standing in front of a white board
a man writes on a white board while teaching a match class
a person is writing a math problem on a whiteboard in front of a class
a teacher is giving a math lesson
a teacher writes math problems out on the board
man explaining a math problem
man teaching about polynomials/
man teaching mathematics in a classroom
teacher showing how to work out problem
teacher teaching in the classroom
teacher showing how to work out problem
a teacher writes math problems out on the board
a man is writing on a whiteboard