Prentice Hall Algebra 1

A rational number is any number that you can write in the form eh over b , comma  where a and b are integers and b not equal to 0 .  A rational number in decimal form is either a terminating decimal such as 5.45 or a repeating decimal such as 0.41666 …, which you can write as 0.41 , 6 bar , .  Each graph below shows a subset of the rational numbers on a number line.

Natural numbers {1, 2, 3, … } A number line has closed circles at 1, 2, and 3.
Whole numbers {0, 1, 2, 3, …} A number line has closed circles at 0, 1, 2, 3, and 4.
Integers { … negative 2 comma negative 1 comma  0, 1, 2, 3, … } A number line has closed circles at negative 2, negative 1, 0, 1, 2, 3, and 4.

An irrational number cannot be represented as the quotient of two integers. In decimal form, irrational numbers do not terminate or repeat. Here are some examples.

0.1010010001 … pi equals . 3.14159265 . dot dot dot

Some square roots are rational numbers and some are irrational numbers. If a whole number is not a perfect square, its square root is irrational.

Rational square root of 4 equals 2 square root of 25 equals 5
Irrational square root of 3 equals . 1.73205080 . dot dot dot square root of 10 equals . 3.16227766 . dot dot dot

Rational numbers and irrational numbers form the set of real numbers.


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Table of Contents

Prentice Hall Algebra 1 Chapter 1 Foundations for Algebra Chapter 2 Solving Equations Chapter 3 Solving Inequalities Chapter 4 An Introduction to Functions Chapter 5 Linear Functions Chapter 6 Systems of Equations and Inequalities Chapter 7 Exponents and Exponential Functions Chapter 8 Polynomials and Factoring Chapter 9 Quadratic Functions and Equations Chapter 10 Radical Expressions and Equations Chapter 11 Rational Expressions and Functions Chapter 12 Data Analysis and Probability Skills Handbook Reference Visual Glossary Selected Answers Index Acknowledgments