CPALMS
Cpalms: Product of Non Zero Rational and Irrational Numbers
[Free Registration/Login Required] In this formative assessment task, students are asked to explain how rational and irrational numbers differ and why the product of a non-zero rational number and an irrational number is irrational....
Alabama Learning Exchange
Alex: Calm and Erratic!
During this lesson, students will learn why numbers are rational or irrational. Rational numbers are numbers that can be written in the form a/b. Irrational numbers cannot be expressed in the form a/b, where a and b are integers.
CK-12 Foundation
Ck 12: Algebra: Basics of Real Numbers Study Guide
This comprehensive study guide highlights the main terms and formulas needed to understand the basics of real numbers. Examples are included.
CK-12 Foundation
Ck 12: Algebra: Irrational Numbers and Radicals Study Guide
This comprehensive study guide highlights the main terms and formulas needed to review irrational numbers and radicals. Examples are included.
Cuemath
Cuemath: Irrational Numbers
Learn how to identify irrational numbers. This lesson reviews the irrational number list, the difference between irrational and rational numbers, and whether or not irrational numbers are real numbers. Examples are provided along with a...
Cuemath
Cuemath: Rational Numbers
This lesson defines rational numbers and teaches you how to identify them. A handy chart is provided that shows the difference between irrational and rational numbers.
CK-12 Foundation
Ck 12: 2.5 Simple Rational Models
This section draws on previous sections that explored how to add, subtract, multiply, and divide rational numbers in order to solve real-world problems involving rational equations. It explores how to apply these procedures in order to...
Quia
Ixl Learning: Irrational Numbers
Brush up on your math skills relating to irrational numbers then try some practice problems to test your understanding.
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Irrational Powers
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.
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Rational and Irrational Number
Math Forum response to the size of the set of rational numbers. Responses investigate the countability of sets and basic set theory.
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Rational Numbers
Math Forum response addressing how many elements are in the set of rational numbers. Responses investigate the countability of sets, and how sets with an infinite number of elements can be counted and compared to other "infinite sets."
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Rational / Irrational Numbers
Math Forum response providing methods to prove that between any two numbers there exist a rational and an irrational number.
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Counting Rationals and Integer
Math Forum response providing a proof that there are as many rational numbers as integers.
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Definitions of Rational, Irrational
Math Forum definition and explanation of rational and irrational numbers, the definitions of mathematics is also addressed.
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Irrational Pi
Math Forum response to the question of why pi is not rational if it is a ratio of circumference to diameter.
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: About Rational Numbers
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.
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Square Roots and Irrational Numbers
Math Forum response to whether square roots of all non-perfect squares are irrational. Contains a proof showing that such cases are, indeed, irrational.
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Irrational Numbers; Rational Square Roots
Dr. Math responds to how one can tell whether a number is rational or irrational. A proof is discussed in the response.
University of Toronto (Canada)
University of Toronto: Rational Numbers
This site from the University of Toronto provides a look at rational numbers and properties of the rational number system.
Wikimedia
Wikipedia: Irrational Number
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.
Doina Popovici
Math Play: Rational and Irrational Numbers Game
An interactive game where students have to determine whether a number is a rational or a irrational number.
Other
The Prime Glossary: Rational Numbers
This site gives a definition of what a rational number is. Gives examples and formulas. Very helpful.
Other
Interactive Real Analysis: Natural Numbers, Integers, Rationals
A rigorous definition of natural numbers, integers, and rationals numbers, using advanced mathematics language. Contains links to proofs.
Sophia Learning
Sophia: Multiplying Rationals: Lesson 2
This lesson demonstrates how to multiply rational numbers using algebraic notation. It is 2 of 6 in the series titled "Multiplying Rationals."