Online Test Banks
Score higher
See Online Test Banks
Learning anything is easy
Browse Online Courses
Mobile Apps
Learning on the go
Explore Mobile Apps
Dummies Store
Shop for books and more
Start Shopping

Identifying Prime Numbers

A prime number is a whole number larger than the number 1 that can be divided evenly only by itself and 1. The first and smallest prime number is the number 2. It’s the only even prime number. All primes after 2 are odd because all even numbers can be divided evenly by 1, themselves, and 2, and so don’t fit the definition of a prime number.

When you recognize that a number is prime, you don’t waste time trying to find things to divide into it when you’re reducing a fraction or factoring an expression. There are so many primes that you can’t memorize or recognize them all, but just knowing or memorizing the primes smaller than 100 is a big help. Here they are:

2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97

blog comments powered by Disqus

Inside Sweepstakes

Win an iPad Mini. Enter to win now!