A boy deiscribes an equation that is written on the marker board.
A person is standing in front of a Blackboard and explaining the formula that is written in it
A guy holding a pen points to a formula on a board and talks.
A boy is standing in front of a dry erase board explaining a mathematical formula.
A kid is explaining a mathematical formula that is on a whiteboard.
A young man points to a white board as he explains a formula.
A man points at a formula written on a whiteboard and starts talking about it.
A man goes up to a white board to discuss an equation.
A young man shows how a particular math problem works while at a white board.
A man is explaining a math equation that has been written on the board.