8.NS.A.1: Know that numbers that are not rational are called irrational. Understand informally that every number has a decimal expansion; for rational numbers show that the decimal expansion repeats eventually, and convert a decimal expansion which repeats eventually into a rational number.
Students will learn the difference between rational and irrational numbers. They'll also learn how to classify numbers as whole numbers, integers, rational numbers, and irrational numbers. In addition to all this, they'll learn how to convert repeating decimals to fractions.