# Ch 2: Praxis I Math: The Real Number System

### About This Chapter

## Praxis I Math: The Real Number System

You'll learn about the different types of numbers, arithmetic with whole numbers, arithmetic calculations with signed numbers and reducing and rebuilding fractions as you work your way through the lessons in this chapter. Video lesson topics also include:

- Finding the least common denominator
- Ordering and comparing fractions
- Changing between improper fraction and mixed number form
- Adding and subtracting like and unlike fractions and mixed numbers
- Multiplying and dividing fractions and mixed numbers
- Practicing with fractions and mixed number arithmetic
- Finding the greatest common factor
- Finding the least common multiple
- Understanding irrational numbers and approximating them by rational numbers
- Finding the greatest common factor

Video instructors will give you a full breakdown of each lesson as they offer advice on how the information they teach can best be used on the Praxis I Math test. To make sure that you're fully prepared for the test and so the lessons remain interesting, a variety of learning approaches will be applied throughout the chapter.

### Objectives of the Real Number System Course

Measuring the mathematical skills and concepts that a college-educated adult might need is the main objective of the Praxis I Math test. The real number system is part of the number and operations portion of the test, which is roughly 32.5% of the skills test. As you complete the lesson's self-assessment quizzes, you'll see how questions are formatted on the Praxis in addition to getting an idea of how familiar you are with the testing methods you're learning.

Typically, there are 15 multiple choice questions about number and operations on the skills test. You'll have 75 minutes to complete the full exam, but you won't be allowed to use a calculator.

### 1. What are the Different Types of Numbers?

Learn all of the different types of numbers: natural numbers, whole numbers, integers, rational numbers, irrational numbers, and real numbers. This video lesson teaches you how to classify any numbers you come across.

### 2. Arithmetic with Whole Numbers

There are four basic mathematical operations: addition, subtraction, multiplication, and division. These four operations are used in a wide range of everyday skills and are the fundamental blocks of arithmetic.

### 3. Arithmetic Calculations with Signed Numbers

Signed numbers are often referred to as integers. Integers include both positive and negative numbers. In this lesson, you will learn how to add, subtract, multiply, and divide integers.

### 4. How to Build and Reduce Fractions

Fractions are a fundamental part of everyday life. Fractions represent a comparison of a part to the whole. To reduce fractions, we will divide by the greatest common factor, or the GCF.

### 5. How to Find Least Common Denominators

Finding a Least Common Denominator is an important tool when working with fractions. To find least common denominators, we will use multiples of our numbers.

### 6. Comparing and Ordering Fractions

Comparing and ordering fractions is way to examine fractions that contain different-sized sets. In order to compare these fractions, you must find a common denominator and make equivalent fractions.

### 7. Changing Between Improper Fraction and Mixed Number Form

Improper fractions and mixed numbers are two different types of fractions. They both have different purposes when using fractions in a problem. In this lesson, you will learn how to convert between these two different forms.

### 8. How to Add and Subtract Like Fractions and Mixed Numbers

When adding and subtracting fractions, you must be sure to have a common denominator. Once you have a common denominator, you just add or subtract your numerators and then your whole numbers. Learn how in this lesson.

### 9. How to Add and Subtract Unlike Fractions and Mixed Numbers

Simple fraction arithmetic gets a little more complicated when our denominators don't match. In this lesson, we'll learn how to add and subtract unlike fractions. Then, we'll do the same with mixed numbers.

### 10. Multiplying Fractions and Mixed Numbers

Multiplying fractions is much more straightforward than adding, subtracting or dividing fractions. In this lesson, learn how it works. We'll also learn how to multiply mixed numbers.

### 11. Dividing Fractions and Mixed Numbers

Dividing fractions and mixed numbers? It sounds daunting, but it's not as tricky as it sounds. In this lesson, we'll learn how to divide fractions and mixed numbers.

### 12. Practice with Fraction and Mixed Number Arithmetic

Adding whole numbers is one thing. But adding fractions and mixed numbers? That's not so simple. Or is it? In this lesson, we'll practice arithmetic with both fractions and mixed numbers.

### 13. How to Find the Greatest Common Factor

If the factors of a number are the different numbers that you can multiply together to get that original number, then the greatest common factor of two numbers is just the biggest one that both have in common. See some examples of what I'm talking about here!

### 14. How to Find the Least Common Multiple

The least common multiple of two numbers is the smallest number that can be divided evenly by your two original numbers. See some examples of what I'm talking about here!

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### Other Chapters

Other chapters within the Praxis Core Academic Skills for Educators - Mathematics (5732): Study Guide & Practice course

- About the Praxis Math Core Test
- Praxis I Math: Square Roots and Exponents
- Praxis I Math: Ratio and Proportions
- Praxis I Math: Algebraic Expressions
- Praxis I Math: Equations and Inequalities
- Praxis I Math: Functions
- Praxis I Math: Congruence and Similarity
- Praxis I Math: Right Triangles and Trigonometry
- Praxis I Math: Circles
- Praxis I Math: Geometric Measurement and Dimension
- Praxis I Math: Basic Statistics and Probability
- Praxis I Math: Categorical and Quantitative Data
- Praxis Core Academic Skills for Educators: Math Flashcards