A bearded man in a black top explains a mathematical calculation.
A man explains a math problem in Spanish while the equation appears beside him.
A bearded man is talking about math in a foreign language.
A man is speaking in Spanish as two diagrams show up to help explain what he is discussing.
A bearded man is explaining how to properly do  mathematics.
A man is talking while a math equation is flashing on a board behind him.
Man describing the designations and functions of different types of math problems.
A person gives a math tutorial as problems flash on the screen.
A bearded man speaking Portuguese explaining how to do math.
A young man is explaining how to do a math problem properly.