Course: Elementary Algebra
Topic: Introduction to Algebra
Subtopic: The Real Number System & Calculators


A scientific calculator is going to be an invaluable tool in this class. With this lesson we learn about the Real Number System as well as how to perform real number operations on a calculator. BTW, "Real numbers" are just all the numbers that you are used to dealing with -- decimals, fractions, the irrational number pi, etc. as opposed to "imaginary numbers" which we will learn about in Intermediate Algebra.


By the end of this topic you should know and be prepared to be tested on:


Terms you should be able to define: decimal, fraction (proper and improper), mixed number, repeating decimal, integer, rational number, irrational number, Real number, opposite (of a number; of an expression), reciprocal (of a number; of an expression), absolute value (of a number; of an expression), exponent, radical, root, number line, order of operations, prime number, composite number, prime factorization, reduce, cancel, simplify.

Supplementary Resources (recommended)

You must be able to use a scientific (or graphing) calculator (app, software, or physical handheld) to perform basic operations including working with signs and fractions and finding powers, roots, and absolute values.

I recommend using a free online calculator or app. One of the most complete is DESMOS.com/calculator, click the keyboard icon at the bottom left of the screen, then click "functions" and explore the tabs. DESMOS also has free apps for mobile devices.

If instead you have a handheld graphing calculator then these sites may help:

Supplementary Resources (optional)

VIDEO: Classifying Sets of Real Numbers, MathIsPower4U
VIDEO: Properties of Real Numbers, MathIsPower4U

Review Pre-Algebra: Feeling like you need to spend a bit of time reviewing pre-algebra / arithmetic topics? I have links to lessons, videos, and some games covering the main topics from pre-algebra in my Just-In-Time Mathematics website and MathIsPower4U.com provides large database of videos at Arthmetic Videos.

rev. 2021-03-31