Education Technology

Middle Grades Math: What is Root 2?

by Texas Instruments


  • Students will use rational numbers to approximate irrational numbers.
  • Students will use the number line diagram to estimate the value of square roots.


  • rational and irrational numbers
  • decimal approximation
  • compound inequality

About the Lesson

This lesson involves estimating the values of two irrational numbers using a number line with increasing precision of scale.
As a result, students will:

  • Estimate square roots by ‘zooming in’ on the values on a number.
  • Find the rational upper and lower bounds for irrational numbers.
  • Explain how to find better and better approximations of an unknown value.