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The Real Number System
The subsets of the real number system are organized in an easy-to-read table. Use the questions at the bottom of the page as an assignment to check for understanding.
Alabama Learning Exchange
Alex: The Real Number System
This lesson focuses on a clear understanding of the real number system by using a variety of teaching strategies. A graphic organizer on a slideshow illustrates how the classifications of numbers relate. A kinesthetic activity helps...
Mathigon
Mathigon: Real, Irrational, Imaginary Numbers
Explore this course in imaginary and complex numbers including topics of integers, real numbers, infinity, transcendental numbers, imaginary and complex numbers.
Texas Instruments
Texas Instruments: Real Numbers
Students learn to identify real numbers as rational numbers and irrational numbers. They review rational numbers as repeating decimals, and irrational numbers as non-repeating decimals. They also review commutative, associative,...
University of Saskatchewan (Canada)
University of Saskatchewan: Decimal Expansions
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...
Cut the Knot
What's a Rational Number?
This question is answered by discussing and comparing rational and irrational numbers. For more advanced levels of Algebra, there are sections that discuss different lemmas of rational numbers and give their proofs.
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...
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.
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.
Common Core Sheets
Common Core Sheets: The Number System 8.ns.1 Worksheets
Print or create worksheets to assess students' understanding of rational and irrational numbers.
Varsity Tutors
Varsity Tutors: Hotmath: Algebra Review: Number Systems
Find a quick, concise explanation of Real Numbers. Other number systems are also defined such as: Natural, Integer, Rational, Irrational and Complex Numbers.
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.
Alabama Learning Exchange
Alex: Those Number Aren't Just Moody.
Rational numbers can sometimes cause problems when they're converted to repeating decimals. That, we can handle. But, what about those irrational numbers that can only be "sort of, like approximated"? How can we expect middle schoolers...
Texas Instruments
Texas Instruments: Number Sets
When you start this activity, students receive a Venn diagram of real number sets (natural, whole, integer, rational, irrational)on their calculator. This same diagram is projected on the Activity Center screen at the front of the room....
Cut the Knot
Cut the Knot!: Polygons: Formality and Intuition
This is a very interesting site about polygons. The site begins by distinguishing between shapes whose sides intersect and polygons whose sides do not overlap. After this short introduction, you will find information regarding area and...
CK-12 Foundation
Ck 12: Algebra: Properties of Rational Numbers
[Free Registration/Login may be required to access all resource tools.] Recognize and identify irrational numbers and the set of real numbers
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.
Cut the Knot
Cut the Knot!: What Is a Number?
Casual and clear but definitely upper-level discussion of rational, real, imaginary, and several other types of numbers. Links to related sites.
Texas A&M University
Wtamu Virtual Math Lab: Intermediate Algebra
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,...
J Coffman
Joseph Coffman's Lecture Notes: Properties of Numbers
The lesson examines properties of real numbers. Students learn about rational numbers, properties of real numbers, and irrational numbers. Examples and an assessment are included.
Math Words
Math Words: Rational Numbers
Mathwords provides a brief description with an easy to read chart that includes all types of real numbers.
Utah Education Network
Uen: Design Your Own Bedroom
Many students dream of designing their ideal bedroom. In this exercise, students will be required to limit their designs by size (as a specific volume) and price (a specific amount). They must design the floor plan, including furniture...
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.
Math Open Reference
Math Open Reference: Number
Resource defines numbers into two main categories, counting numbers and scalars. It also gives examples of number notation.