

How to Find Square Roots Using Prime Factorization Method
Have you ever wondered why students are a little uneasy with the subject of Mathematics? Is the subject actually difficult to understand and study? Is it really hard to score good marks in math? Will a student ever fall in love with the subject?
The subject experts at Vedantu patiently have studied the challenges of students across their network and have made the following conclusions -
Students find a subject difficult when they fail to understand the basics clearly
The teaching method and learning techniques also plays a role in building a student’s relationship with a subject
The guidance and the reading materials made available to the students also decide their interest in the subject
Considering all these problems, our team tries their best to make reading more interesting and fun for the students. Students can download the free reading materials where concepts are explained in the easiest language. Video lectures are made available to make students understand better.
This particular article brings another mathematical concept, explained in detail for the students to grasp the concept and get familiar with mathematical concepts.
Table of content -
Square Root - Introduction
Square Root Definition
Method of finding the square root
Prime factorization method
Solved examples
Fun facts
Frequently asked questions
Square Root Basics
We all are aware of a geometrical shape, the square. Square is a geometrical shape which has four sides of equal length and angles equal to 900. Square, being a two-dimensional shape, covers a specific surface of the plane. This region covered by the square is called its area. Area of a square is calculated as the side x side. If the area of the square is given and its side is to be determined then we use an operation in Mathematics called the square root. For example, if the area of a square is 9 sq. units, then its side measures 3 units which is calculated as the square root of 9.
Square Root Definition
Square of a number is another number obtained by multiplying the number by itself. Square root is the inverse operation of square. Square root of a number is that number which when multiplied by itself, gives the number whose square root is to be determined as the answer. For example, when 7 is multiplied by itself, the product obtained is 49. Therefore, we can say that the square root of 49 is 7. Square root of a number is represented by the symbol ‘√’. It can also be represented exponentially as the number to the power ½ . The square root of a number ‘A’ can be represented as √A or A1/2. Any number in Mathematics will have two roots of equal magnitude and opposite sign.
Methods to Find Square Root of a Number
Square root of a number can be determined by various methods. A few popular methods used to find the square root of a number are:
Guess and Check Method.
Average Method.
Repeated Subtraction Method.
Prime Factorization method.
Long Division Method.
Number Line Method.
The repeated subtraction method and prime factorization method is applicable only for perfect square numbers. Perfect square numbers are the numbers whose square roots are integers. The examples for perfect square numbers are 1, 4, 9, 16, 25 ……
How to Find the Square Root of a Number by Prime Factorization Method?
Prime factorization method is a method in which the numbers are expressed as a product of their prime factors. The identical prime factors are paired and the product of one element from each pair gives the square root of the number. This method can also be used to find whether a number is a perfect square or not. However, this method cannot be used to find the square root of decimal numbers which are not perfect squares.
Example: Evaluate the root of 576.
Solution: 576 is factorized into its prime factors as follows.
So, 576 can be written as a product of prime numbers as: 576=2×2×2×2×2×2×3×3
Square root of 576 = 2×2×2×3=24
Square Root by Prime Factorization Example Problems
1. Find the square root of 1764 using the prime factorization method.
Solution: Step 1: The given number is resolved into its prime factors.
1764=2×2×3×3×7×7
Step 2:
Identical factors are paired.
1764=2×2×3×3×7×7
Step 3: One factor from each pair is chosen and the product is found to get the square root. √1764=2×3×7
√1764=42
2. Check whether 11025 is a perfect square or not. If it is a perfect square, find its square root by factorization method.
Solution:
Using prime factorization method, 11025 can be written as the product of its primes as:
11025=3×3×5×5×7×7
All the prime factors can be grouped into pairs of identical factors. No prime factor is left all alone. Hence 11025 is a perfect square number.
√11025=3×5×7=105
3. Find the smallest number to be multiplied by 8712 to make it a perfect square number.
Solution:
Using the prime factorization method, 8712 can be factorized as
8712=2×2×2×3×3×11×11
When the identical factors are paired, 8712 can be written as:
8712=2×2×2×3×3×11×11
So, the number 8712 should be multiplied by 2 in order to get a perfect square number.
Fun Facts:
Any real number has two square roots: a positive root and a negative root. Both the roots are the same in magnitude but the signs are opposite. So, the square root of the number ‘x’ can be written as ±√x.
The square root of a square of any number is the number itself.
The square root of non-perfect square numbers cannot be determined using the prime factorization method. However, one can determine the number to be multiplied or divided by the given number to make it a perfect square.
FAQs on Square Root Prime Factorization Explained
1. What is the prime factorization method for finding a square root?
The prime factorization method is a way to find the square root of a perfect square by breaking the number down into its prime factors. The core idea is that every prime factor of a perfect square will appear an even number of times. By grouping these factors into identical pairs, you can easily determine the square root.
2. What are the steps to find a square root using the prime factorization method?
To find the square root of a number using this method, as per the CBSE/NCERT curriculum for the 2025-26 session, you should follow these steps:
Step 1: Find the prime factors of the given number by dividing it by prime numbers until the quotient is 1.
Step 2: Group the prime factors into pairs of identical numbers.
Step 3: Take one factor from each pair.
Step 4: Multiply all the factors you selected in the previous step. The resulting product is the square root of the original number.
3. Can you explain how to find the square root of 1764 using prime factorization?
Certainly. Let's find the square root of 1764 with an example:
First, we find the prime factors of 1764. We get: 1764 = 2 × 2 × 3 × 3 × 7 × 7.
Next, we group these factors into identical pairs: (2 × 2) × (3 × 3) × (7 × 7).
Now, we take one number from each pair: 2, 3, and 7.
Finally, we multiply these numbers: 2 × 3 × 7 = 42.
Therefore, the square root of 1764 is 42.
4. What happens if a number's prime factors do not form perfect pairs?
If any prime factor of a number does not have a pair, it means the number is not a perfect square. The prime factorization method is only used to find the exact square root of perfect squares. The presence of an 'unpaired' prime factor indicates that the square root of the number will be an irrational number (a non-repeating, non-terminating decimal).
5. How is the prime factorization method different from the long division method for finding square roots?
The two methods differ in their application and process:
Applicability: The prime factorization method only works for finding the exact square root of perfect squares. The long division method is a universal algorithm that can find the square root of any positive number, including non-perfect squares and decimals, to a desired precision.
Process: Prime factorization involves breaking a number down into its constituent primes. Long division is an iterative process of pairing digits and estimating divisors, similar to standard division.
6. Why can't a prime number be a perfect square?
This is due to the fundamental definitions of prime and square numbers. A key property of a perfect square is that all its prime factors must occur an even number of times. By definition, a prime number has exactly two factors: 1 and itself. Its prime factorization consists of only one prime factor (the number itself). Since 'one' is an odd number, its prime factors cannot be grouped into pairs, and therefore, a prime number can never be a perfect square.
7. What is the real-world importance of prime factorization?
Prime factorization is not just a classroom concept; it is fundamental to modern technology. Its most significant real-world application is in cryptography, particularly in the RSA algorithm used to secure online data transmission for banking, e-commerce, and communications. The security of this system relies on the fact that it is extremely difficult to find the large prime factors of a given composite number, making codes hard to break.

















