The reading material provided on this page for Prime Numbers is specifically designed for students in grades 5 and 6.

Prime Numbers

A prime number is a natural number which is only divisible by 1 and itself. This means a prime number is a positive integer greater than 1 that has no factor other than 1 and itself. The prime number starts from 2, 2 is the smallest prime number.

Numbers 2, 3, 5, 7, 11, and 13 are all prime numbers, but 4, 6, 8, 9, and 10 are not, because they can be divided evenly by numbers other than 1 and themselves.

For example, 5 is prime because the only ways of writing it as a product, 1 × 5 or 5 × 1, involve 5 itself.

However, 4 is a composite number because it is a product (1 x 2 × 2) in which both numbers are smaller than 4.

NOTE: 1 is neither a prime nor composite number. While 1 is only divisible by itself and 1, it does not have exactly two divisors, since the definition of a prime number requires that a number have at least two distinct divisors (not counting 1 and itself).

Composite Number

A composite number is a positive integer that has at least one positive divisor other than 1 and itself. In other words, a composite number is a number that is not a prime number.

For example, the number 6 is a composite number because it has divisors other than 1 and 6, namely 2 and 3. On the other hand, the number 7 is a prime number because its only positive divisors are 1 and 7.

Prime Numbers from 1 to 100

There are 25 prime numbers from 1 to 100. The list of prime numbers from 1 to 100 are listed below:

How to Find Prime Numbers?

Step 1: First understand what is a prime number exactly. A prime number is a positive integer that is only divisible by 1 and itself.

Step 2: Start with the number 2, as it is the first prime number.

Step 3: Divide the number by all integers less than itself, starting with 2. For example, if you are checking the number 5 is prime, divide it by 2, 3, and 4.

Step 4: If the number is not divisible by any of the integers, it is a prime number. In the example of 5, it is not divisible by 2, 3, or 4, so it is a prime number.

Step 5: Repeat the process for the next number in sequence, checking if it is prime.

Step 6: Continue the process until you reach the number you want to check.

Quick Video Recap

In this section, you will find interesting and well-explained topic-wise video summary of the topic, perfect for quick revision before your Olympiad exams.

This is Curio, your AI Doubt Solver. Here to help you with any educational doubts you encounter while preparing for your Olympiad exams. Feel free to ask questions and learn!

Share Your Feedback

CREST Olympiads has launched this initiative to provide free reading and practice material. In order to make this content more useful, we solicit your feedback.

Do share improvements at info@crestolympiads.com. Please mention the URL of the page and topic name with improvements needed. You may include screenshots, URLs of other sites, etc. which can help our Subject Experts to understand your suggestions easily.