1. Rational numbers include integers and fractions, and can be written in the form x/y where x and y are integers. 2. Addition, subtraction, multiplication, and division of rational numbers can be performed by finding equivalent fractions with a common denominator or by using algebraic expressions. 3. Two fractions are equal if their numerators divided by their denominators are equal (i.e. if aq = bp, where a/b and p/q are the fractions).