Lesson: Rational and Irrational Numbers Mathematics • 8th Grade

Students will be able to

• define what makes a number rational or irrational, in particular,
  • if a number can be written in the form , then it is rational,
  • if it is a repeating decimal number (e.g., 0.66666…), then it is rational,
  • if it is a terminating decimal number (e.g., 0.259574), then it is rational,
  • if a decimal number is neither terminating nor repeating (e.g., ), then it is irrational,
• understand that rational and irrational numbers are disjoint sets,
• identify rational numbers and prove that they are rational using the above properties,
• identify irrational numbers such as roots of nonperfect squares or cubes and pi,
• identify whether the solution of a simple equation will be rational or irrational without finding its value.