APA stands for the American Psychological Association, and the point of using APA style is to create a standardized method of referencing materials. Writing about money in this form requires you to follow certain rules for consistency. For more examples, reference the APA Style Guide.

Use the dollar sign in all instances that demand numerical specificity. Only spell out "dollars" in casual or abstract cases. For example, "The book cost $4, but dollars are flowing overseas."

Use a singular verb for specific amounts. For example, "He said $500,000 is what they want." The verb "is" is used instead of "are."

Use the dollar sign and up to two decimal places for amounts of more than $1 million. Do not use hyphens. For example, "He is worth $4.35 million. He is worth exactly $4,351,242. He proposed a $300 billion budget."