Finding the Prime Numbers

For finding the prime numbers we write all the whole numbers from 1 to 100 in a 10-square table and then follow the following steps.



Step 1: 1 is a unique number, so we do not consider it.

Step 2: We cross out all the multiples of 2 except 2.

Step 3: We cross out all the multiples of 3 except 3.

Step 4: We cross out all the multiples of 5 except 5.

Step 5: We cross out all the multiples of 7 except 7.

Step 6: Now, we encircle all the remaining numbers except 1.

Finding the Prime Numbers

All the numbers encircle are prime numbers. Those which are crossed out are the composite numbers. 1 is a unique number.

We see that 25 numbers are prime numbers out of the first 100 numbers.

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










4th Grade Math Activities

From Finding the Prime Numbers to HOME PAGE




Didn't find what you were looking for? Or want to know more information about Math Only Math. Use this Google Search to find what you need.



New! Comments

Have your say about what you just read! Leave me a comment in the box below. Ask a Question or Answer a Question.




Share this page: What’s this?

Recent Articles

  1. Multiplication Table | Learn Tables from 0 – 25 | Multiplication Table

    Jan 14, 25 11:09 PM

    multiplication table
    In math multiplication table we will learn the tables from 0 – 25. These multiplication tables help the students to learn the essential multiplication facts. Multiplication tables are very important f…

    Read More

  2. 3rd Grade Math Worksheets |3rd Grade Math Sheets|3rd Grade Math Lesson

    Jan 14, 25 11:02 PM

    3rd Grade Math Worksheets
    3rd grade math worksheets is carefully planned and thoughtfully presented on mathematics for the students. Teachers and parents can also follow the worksheets to guide the students.

    Read More

  3. 3rd Grade Subtraction Worksheet | 3-Digit Subtraction Worksheets | Ans

    Jan 14, 25 01:57 PM

    Fill in the Missing Numbers Subtraction and Addition
    In 3th Grade Addition Worksheet we will solve how to subtract 3-digit numbers by expansion, subtraction of 3-digit numbers without regrouping, subtraction of 3-digit numbers with regrouping, propertie…

    Read More

  4. Facts about Subtraction | Subtraction of Small Numbers|Solved Examples

    Jan 14, 25 12:29 AM

    The operation to finding the difference between two numbers is called subtraction. Let us know some facts about subtraction which will help us to learn subtraction of large numbers. 1. Subtraction wit…

    Read More

  5. Word Problems on Subtraction |Worksheet on Subtraction Word Problems |

    Jan 14, 25 12:21 AM

    Subtraction Problem
    In word problems on subtraction we need to read the question carefully and understand what we need to find out. We know, in subtraction the larger number from which we subtract the other number (the s…

    Read More