# Ch 5: ORELA Middle Grades Math: Number Theory

### About This Chapter

## ORELA Middle Grades Math: Number Theory - Chapter Summary

This chapter dives into prime and composite numbers, common factors and multiples and factorization. Our experienced instructors bring you memorable lessons with engaging graphics on topics including:

- Identifying composite and prime numbers
- Defining odd and even numbers
- Finding the prime factorization of numbers and exponents
- Identifying greatest common factors and least common multiples
- Finding least common multiples with prime factorization
- Working with common multiples and factors in word problems

Along with the short videos, you will get a lesson transcript with key terms bolded for easy reference and a brief quiz to test your retention of main points. Take the chapter quiz as well to get more practice in answering the kinds of questions you will see when taking the ORELA Middle Grades Mathematics test, returning to lessons where you find you may need additional review.

### ORELA Middle Grades Math: Number Theory Chapter

Of the 150 multiple-choice questions you will have to answer on test day, the parent content domain of estimation and rounding--Number Sense and Operations--accounts for 17%, though you may also use principles covered here to answer questions quickly in other domains. You will have four hours and 15 minutes to complete this test, and must do so using only the on-screen calculator and the notes material they provide at the testing center. You must achieve a scaled score of 225 or higher on the 100-300 scale to pass and receive this endorsement on your Oregon educator's license. You will receive your scaled score before leaving the testing center, but the two score reports you are sent will take about two weeks to get to you.

Get ready for test day with the review and test practice presented in this chapter. While we can't promise you a passing score, we can indeed promise that your time here will give you plenty of review on key topics and relevant practice, helping to boost your competence and confidence before sitting down to take the test.

### 1. What Are Prime Numbers? - Definition & Examples

In this lesson, we'll do a brief review of factors, and then learn how factors make prime numbers unique. You can also test your knowledge with a brief quiz.

### 2. What Are Composite Numbers? - Definition & Examples

In this lesson, you'll learn what composite numbers are and briefly touch on prime numbers. You'll also learn a couple of rules about composite numbers. Then, you can test your new knowledge with a brief quiz.

### 3. What Are Odd & Even Numbers? - Definition & Examples

In this lesson, you'll learn what odd and even numbers are with the help of some visual aids. You'll also learn some interesting properties of odd and even numbers. Then, you can test your new knowledge with a brief quiz.

### 4. How to Find the Prime Factorization of a Number

The prime factorization of a number involves breaking that number down to its smallest parts. This lesson will show you two different ways to discover the prime factorization of any number.

### 5. Finding the Prime Factorization with Exponents

After watching this video lesson, you will be able to factor any number using just prime numbers and exponents. Learn how to break apart any number you are given. Then, test your new knowledge with some examples.

### 6. 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!

### 7. 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!

### 8. Using Prime Factorizations to Find the Least Common Multiples

Finding the least common multiple can seem like a lot of work. But we can use prime factorization as a shortcut. Find out how and practice finding least common multiples in this lesson.

### 9. Word Problems: Greatest Common Factor & Least Common Multiple

In this video lesson, you will learn what kinds of word problems you can expect to see that involve the greatest common factor or the least common multiple. Learn what you need to do to understand these problems and then to solve them.

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### Other Chapters

Other chapters within the ORELA Middle Grades Mathematics: Practice & Study Guide course

- ORELA Middle Grades Math: Basic Arithmetic Operations
- ORELA Middle Grades Math: Solving Math Word Problems
- ORELA Middle Grades Math: Properties of Numbers
- ORELA Middle Grades Math: Estimating & Rounding
- ORELA Middle Grades Math: Roots & Radical Expressions
- ORELA Middle Grades Math: Exponents & Exponential Expressions
- ORELA Middle Grades Math: Scientific Notation
- ORELA Middle Grades Math: Simplifying Whole Number Expressions
- ORELA Middle Grades Math: Integers
- ORELA Middle Grades Math: Rational Numbers
- ORELA Middle Grades Math: Introduction to Fractions
- ORELA Middle Grades Math: Operations with Fractions
- ORELA Middle Grades Math: Introduction to Decimals
- ORELA Middle Grades Math: Operations with Decimals
- ORELA Middle Grades Math: Percents
- ORELA Middle Grades Math: Money & Consumer Math
- ORELA Middle Grades Math: Number Patterns & Sequences
- ORELA Middle Grades Math: Properties of Functions
- ORELA Middle Grades Math: Graphing Functions
- ORELA Middle Grades Math: Negative Numbers
- ORELA Middle Grades Math: Absolute Value
- ORELA Middle Grades Math: Inequalities
- ORELA Middle Grades Math: Factoring
- ORELA Middle Grades Math: Monomials & Polynomials
- ORELA Middle Grades Math: Writing Algebraic Expressions
- ORELA Middle Grades Math: Basic Algebraic Expressions
- ORELA Middle Grades Math: Algebraic Distribution
- ORELA Middle Grades Math: Writing & Solving One-Step Equations
- ORELA Middle Grades Math: Writing & Solving Two-Step Equations
- ORELA Middle Grades Math: Simplifying & Solving Rational Expressions
- ORELA Middle Grades Math: The Coordinate Graph
- ORELA Middle Grades Math: Linear Equations
- ORELA Middle Grades Math: Systems of Linear Equations
- ORELA Middle Grades Math: Rates, Ratios & Proportions
- ORELA Middle Grades Math: Measurements
- ORELA Middle Grades Math: Perimeter & Area
- ORELA Middle Grades Math: Polyhedrons & Geometric Solids
- ORELA Middle Grades Math: Symmetry, Similarity & Congruence
- ORELA Middle Grades Math: Properties of Lines
- ORELA Middle Grades Math: Angles
- ORELA Middle Grades Math: Triangles
- ORELA Middle Grades Math: Triangle Theorems & Proofs
- ORELA Middle Grades Math: Similar Polygons
- ORELA Middle Grades Math: The Pythagorean Theorem
- ORELA Middle Grades Math: Quadrilaterals
- ORELA Middle Grades Math: Circles
- ORELA Middle Grades Math: Circular Arcs & Measurement
- ORELA Middle Grades Math: Transformations
- ORELA Middle Grades Math: Data & Graphs
- ORELA Middle Grades Math: Statistics
- ORELA Middle Grades Math: Data Collection
- ORELA Middle Grades Math: Samples & Populations
- ORELA Middle Grades Math: Probability
- ORELA Middle Grades Math: Sets
- ORELA Middle Grades Mathematics Flashcards