Purple Math
Purplemath: Number Types
This site explores the different types of numbers: natural numbers, whole numbers, integers, and rational and irrational numbers. Content includes some practice questions.
Other
The Prime Glossary: Rational Numbers
This site gives a definition of what a rational number is. Gives examples and formulas. Very helpful.
Khan Academy
Khan Academy: Classify Numbers
Practice classifying numbers as whole, integer, rational, and irrational. Students receive immediate feedback and have the opportunity to try questions repeatedly, to watch a video, or ask for a hint.
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.
National Institute of Educational Technologies and Teacher Training (Spain)
Ministerio De Educacion: Los Numerous Reales
In this module you will learn about rational and irrational numbers.
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Numbers
Math Forum response to request for information on various number sets. Also defined and discussed are integers, natural numbers, whole numbers, irrational numbers, transcendental numbers, and algebraic numbers.
CK-12 Foundation
Ck 12: Arithmetic: Properties of Rational Numbers
[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...
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.
Math Is Fun
Math Is Fun: The Evolution of Numbers
Discusses what numbers are and how our understanding of them has evolved over thousands of years, from simple counting to negative numbers and irrational numbers, for example. Includes a set of practice questions where students identify...
CK-12 Foundation
Ck 12: Algebra: Sets and Symbols
[Free Registration/Login may be required to access all resource tools.] Classify real numbers as rational numbers, whole numbers, integers, and irrational numbers.
CK-12 Foundation
Ck 12: Arithmetic: Conversion of Decimals, Fractions, and Percent
[Free Registration/Login may be required to access all resource tools.] Understand, identify and find equivalent forms of rational numbers
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 Pi
Math Forum response to the question of why pi is not rational if it is a ratio of circumference to diameter.
Math.com
Math.com: The Language of Algebra: Definitions
The resource investigates the algebra vocabulary. Detailed definitions, examples, and practice problems are included.
Houghton Mifflin Harcourt
Holt, Rinehart and Winston: Homework Help Independent Practice: Real Numbers
Get independent practice working with real numbers. Each incorrect response gets a text box explanation and another try. Correct responses are confirmed.
CK-12 Foundation
Ck 12: Arithmetic: Order of Real Numbers Grade 8
[Free Registration/Login may be required to access all resource tools.] Learn how to classify, order, and graph real numbers.
Washington State University
Washington State University: Sets & Other Basic Concepts
Washington State University provides an introduction to sets and subsets and the symbols used to represent them.