Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: 8.ns Comparing Rational and Irrational Numbers

For Teachers 8th Standards
For this task, 8th graders are presented with pairs of rational or irrational numbers. They must state which number in the pair is higher and explain their thinking. Aligns with 8.NS.A.2.
Activity
Wolfram Research

Wolfram Math World: Irrational Numbers

For Students 9th - 10th Standards
This math site explains what it means for a number to be irrational and names various persons who have proven the irrationality of some numbers, the site also gives several numbers who are thought to be irrational yet have not been...
Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: 8.ns Identifying Rational Numbers

For Teachers 8th Standards
For this task, 8th graders are presented with a mixed set of eight different numbers and must identify them as rational or irrational and explain how they know. Aligns with 8.NS.A.1.
Unit Plan
CK-12 Foundation

Ck 12: Algebra: Properties of Rational Numbers

For Students 7th
[Free Registration/Login may be required to access all resource tools.] Recognize and identify irrational numbers and the set of real numbers
Unit Plan
CK-12 Foundation

Ck 12: Algebra: Irrational Square Roots

For Students 8th Standards
[Free Registration/Login may be required to access all resource tools.] Find approximate solutions to equations involving irrational numbers.
Unit Plan
TED Talks

Ted: Ted Ed: The Psychology Behind Irrational Decisions

For Students 9th - 10th Standards
Often people make decisions that are not "rational" from a purely economical point of view. Sara Garofalo explains heuristics, problem-solving approaches based on previous experience and intuition rather than analysis. [4:39]
Unit Plan
CK-12 Foundation

Ck 12: Arithmetic: Comparison of Rational Numbers

For Students 7th
[Free Registration/Login may be required to access all resource tools.] Compare and order rational numbers on a number line and by using inequality symbols
Unit Plan
CK-12 Foundation

Ck 12: Arithmetic: Properties of Rational Numbers

For Students 6th - 9th Standards
[Free Registration/Login may be required to access all resource tools.] In this lesson students identify rational numbers as the ratio of two integers. Students examine guided notes, review guided practice, watch instructional videos and...
Handout
Free Math Help

Free Math Help: Algebra Lesson: Rational Numbers

For Students 9th - 10th Standards
Learners examine the set of real numbers. The resource includes detailed explanations about rational and irrational numbers. It provides example problems.
Handout
Math Open Reference

Math Open Reference: Irrational Number

For Students 9th - 10th Standards
Learn about irrational numbers with this easy reference guide. Provides a detailed definition and examples that enhance further explanation. Provides links to related topics.
Whiteboard
ClassFlow

Class Flow: Rational and Irrational Numbers

For Teachers 6th - 8th Standards
[Free Registration/Login Required] By the end of the lesson, students will classify numbers into number families to help understand how to distinguish the difference between rational and irrational numbers. Students will demonstrate this...
Activity
National Council of Teachers of Mathematics

The Math Forum: Ask Dr. Math: About Rational Numbers

For Students 9th - 10th Standards
Math Forum response giving a rather thorough overview of rational and irrational numbers, with a brief look at the history of these and other number sets.
Handout
Wikimedia

Wikipedia: Irrational Number

For Students 9th - 10th Standards
At this site from Wikipedia you can learn the definition of an irrational number, then look at examples and explanations of why some numbers are irrational and others are not.
Activity
National Council of Teachers of Mathematics

The Math Forum: Ask Dr. Math: Rational and Irrational Number

For Students 9th - 10th Standards
Math Forum response to the size of the set of rational numbers. Responses investigate the countability of sets and basic set theory.
Handout
Other

The Prime Glossary: Rational Numbers

For Students 9th - 10th Standards
This site gives a definition of what a rational number is. Gives examples and formulas. Very helpful.
Unknown Type
University of Saskatchewan (Canada)

University of Saskatchewan: Decimal Expansions

For Students 9th - 10th
The University of Saskatchewan's Department of Mathematics and Statistics provides high school students with an online tutorial on decimal expansions. It begins with a focus on decimal representation of real numbers, followed by how this...
Unit Plan
Texas A&M University

Wtamu Virtual Math Lab: Intermediate Algebra

For Students 9th - 10th
This site is a tutorial for students in algebra 2 or for those who need a refresher. The site has explanations, definitions, examples, practice problems and practice tests are found covering topics such as linear equations, graphing,...
Activity
Lawrence Hall of Science

The Math Page: Skill in Algebra: Radicals: Rationals & Irrationals

For Students 9th - 10th Standards
Here is a site that clearly and thoroughly explains many topics related to radicals. There are example problems solved, problems for the student to attempt, and answers to the student problems. Point this site out to students who have...
Graphic
Math Words

Math Words: Rational Numbers

For Students 9th - 10th Standards
Mathwords provides a brief description with an easy to read chart that includes all types of real numbers.
Handout
Other

Platonic Realms: Conic Sections

For Students 9th - 10th Standards
A proof to show that the square root of two is an irrational number, followed by a shorter and even more beautiful proof.
Interactive
Doina Popovici

Math Play: Rational and Irrational Numbers Game

For Students 7th - 9th Standards
An interactive game where students have to determine whether a number is a rational or a irrational number.
Activity
National Council of Teachers of Mathematics

The Math Forum: Ask Dr. Math: Irrational Powers

For Students 9th - 10th Standards
Math Forum response considering whether an irrational number taken to an irrational power yields a rational or irrational number. Responses include a method of generating irrational #s x & y such that x^y is rational.
Activity
National Council of Teachers of Mathematics

The Math Forum: Ask Dr. Math: Square Roots and Irrational Numbers

For Students 9th - 10th Standards
Math Forum response to whether square roots of all non-perfect squares are irrational. Contains a proof showing that such cases are, indeed, irrational.
Activity
National Council of Teachers of Mathematics

The Math Forum: Ask Dr. Math: Irrational Numbers; Rational Square Roots

For Students 9th - 10th Standards
Dr. Math responds to how one can tell whether a number is rational or irrational. A proof is discussed in the response.

Other popular searches