Mathematics Grade 7 15 min

Prime or Composite

Prime or Composite

Tutorial Preview

1

Introduction & Learning Objectives

Learning Objectives Define prime numbers. Define composite numbers. Distinguish between prime and composite numbers. Identify all factors of a given whole number. Determine if a given whole number (up to 100) is prime or composite. Explain why 0 and 1 are neither prime nor composite. Apply divisibility rules to aid in classifying numbers. Ever wonder why some numbers seem 'lonely' with only two friends, while others have a whole party of friends? 🤔 Let's uncover the secret lives of numbers! In this lesson, you'll learn to classify whole numbers greater than 1 as either prime or composite. Understanding these classifications is fundamental to number theory and helps us break down numbers into their basic building blocks, which is super useful in many a...
2

Key Concepts & Vocabulary

TermDefinitionExample Whole NumberThe set of non-negative integers: 0, 1, 2, 3, and so on, without fractions or decimals.5, 12, 0, 100 are all whole numbers. FactorA whole number that divides another whole number exactly, leaving no remainder.The factors of 12 are 1, 2, 3, 4, 6, and 12 because each divides 12 evenly. Prime NumberA whole number greater than 1 that has exactly two distinct positive factors: 1 and itself.7 is a prime number because its only factors are 1 and 7. Composite NumberA whole number greater than 1 that has more than two distinct positive factors.10 is a composite number because its factors are 1, 2, 5, and 10 (more than two factors). Divisibility RulesShortcuts or tests to determine if a number is divisible by another number without performing long division.A number...
3

Core Formulas

Prime Number Rule A whole number $p > 1$ is prime if its only positive factors are $1$ and $p$. To identify a prime number, you must find exactly two factors: 1 and the number itself. If you find any other factor, it's not prime. Composite Number Rule A whole number $c > 1$ is composite if it has at least one positive factor other than $1$ and $c$. To identify a composite number, you need to find at least one factor other than 1 and the number itself. This means it has more than two factors. Special Cases of 0 and 1 The numbers $0$ and $1$ are neither prime nor composite. Always remember these two exceptions. 1 only has one factor, and 0 has an infinite number of factors, so they don't fit the definitions.

5 more steps in this tutorial

Sign up free to access the complete tutorial with worked examples and practice.

Sign Up Free to Continue

Sample Practice Questions

Easy
According to the definition provided, which of the following best describes a prime number?
A.whole number greater than 1 that has exactly two distinct positive factors: 1 and itself.
B.Any whole number that is not even.
C.whole number that has more than two factors.
D.whole number that can only be divided by 1.
Easy
What is the definition of a composite number?
A.whole number with exactly two factors.
B.whole number greater than 1 that has more than two distinct positive factors.
C.Any whole number that is even.
D.whole number that is not prime.
Easy
Which of the following numbers is a prime number?
A.9
B.15
C.17
D.21

Want to practice and check your answers?

Sign up to access all questions with instant feedback, explanations, and progress tracking.

Start Practicing Free

More from Number Theory

Ready to find your learning gaps?

Take a free diagnostic test and get a personalized learning plan in minutes.