Financial Statements

It is said, "Numbers can be made to say anything." If this is true, what measures can be used to ensure that data is correctly interpreted and analyzed?

A close friend of yours, who is a history major and who has not had any college courses or experience in business, is receiving financial statements from companies in which he has minor investments. He asks you what he needs to know to interpret and evaluate the financial statement data he is receiving. What would you tell him? He also wants to know what this quote means: "The significance of financial statement data is not in the amount alone." Discuss how you would explain these issues to him.