## Elementary Math (K-6th) Tutorial

*How to Find Prime Numbers In A Chart of 1 to 100?*

#### Intro

Finding prime numbers in a chart of 1 to 100 can be helpful to memorize and to understand with dealing with small numbers. However, a chart would not be practical for doing homework, a quiz, or a test. Nevertheless, the steps that I have provided in dealing with numbers from 1 to 100 is a basic way to find the prime numbers and the composite numbers, with the exception of 1.

#### Sample Problem

Suppose I have a chart from 1 to 100. Which numbers should I circle that are prime numbers? Which numbers should I cross out that are composite numbers?

#### Solution

1. Cross off 1.

2. Circle 2 and cross off every multiple of 2 like 4,6,8,10,12,…

3. Circle 3 and cross off every multiple of 3 like 6,9,12,15,18,…

4. Circle 5 and cross off every multiple of 5 like 10,15,20,25,30,…

5, Circle 7 and cross off every multiple of 7 like 14,21,28,35,42,…

6. Circle every number that is not crossed out.

-Make sure to cross out the 1 and the multiples of 2,3,5, and 7 before circling everything that is not crossed out.

# About The Author

Math, Biology, And History Instructor |

Hello. I am Kisung Yoon, and I am a senior in high school. I am currently in the ARISTA Honor Society, and I have tutored my fellow students from my school in Algebra I, Algebra 2, Global History, US History, and Biology. Not only that, I also tutored my younger sisters on the standardized tests mai... |