Lesson 5.1: Use Properties of Rational and Irrational NumbersIn this lesson students will learn why the sum or product of two rational numbers is rational; that the sum of a rational number and an irrational number is irrational and that the product of a nonzero rational number and in irrational number is irrational. Students will address how rational numbers and irrational numbers are alike and how they are different. For example, we use the ? in the formula for the area of a circle and the ? in the formula of an ellipse as an example of an irrational number. In this lesson we will calculate the area of a typical putting green on a golf course and the area of a track field, which is in the shape of an ellipse.