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Understanding Squares and Square Roots in Maths

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What Are Squares and Square Roots Definition Formula and Solved Examples

The concept of Squares and Square Roots plays a key role in mathematics and is widely applicable to real-life situations as well as in exams like Class 8 Maths, Olympiads, and other competitive tests.


What Is Squares and Square Roots?

Squares and Square Roots are basic arithmetic concepts in which the square of a number (written as n2) means multiplying the number by itself, and the square root (written as √n) is the value that, when multiplied by itself, gives the original number. You’ll find this concept applied in simplification of calculations, handling exponents and roots, quadratic equations, and even the Pythagoras theorem.


Key Formula for Squares and Square Roots

Here’s the standard formula:
Squares: \( n^{2} = n \times n \)
Square Roots: \( \sqrt{n} = x \) such that \( x \times x = n \)


Squares and Square Roots Table (1–30)

Number Square (n2) Square Root (√n)
111.000
241.414
391.732
4162.000
5252.236
6362.449
7492.646
8642.828
9813.000
101003.162
... ...... ...... ...
256255.000
309005.477

Cross-Disciplinary Usage

Squares and square roots are not only useful in Maths but play an important role in Science, Engineering, Architecture, Computer Science, and daily problem-solving. For example, Pythagorean theorem uses squares and square roots to find the length of triangle sides, and square roots are essential for statistics and algebra.


Step-by-Step Illustration: Finding Square Root by Prime Factorization

  1. Let’s find √144:
    Step 1: Find the prime factors of 144
    144 = 2 × 2 × 2 × 2 × 3 × 3
  2. Group similar factors into pairs:
    (2 × 2) × (2 × 2) × (3 × 3)
  3. Select one from each pair and multiply:
    2 × 2 × 3 = 12
  4. Final Answer: √144 = 12

Speed Trick or Vedic Shortcut

Here’s a shortcut for squaring numbers ending with 5:

  1. To find the square of 65, take the first digit(s): 6
  2. Multiply it by the next integer: 6 × 7 = 42
  3. Add 25 at the end: 4225
  4. So, 652 = 4225

Such tricks make calculations faster, especially in exams. Explore more on Square Root Tricks at Vedantu.


Try These Yourself

  • Write down all perfect squares between 1 and 50.
  • Is 81 a perfect square? What is its square root?
  • Use prime factorization to find the square root of 225.
  • List numbers from 1 to 20 whose square roots are not integers.

Frequent Errors and Misunderstandings

  • Confusing squaring a number (n × n) with doubling or multiplying by 2.
  • Thinking every number has an integer square root.
  • Forgetting that negative numbers don’t have real square roots.
  • Confusing square roots with cube roots.

Relation to Other Concepts

The idea of squares and square roots connects closely with exponents, cube roots, Pythagorean triples, and even algebraic equations. Mastering squares and roots will make chapters like Exponents and Powers and Cubes and Cube Roots much easier.


Classroom Tip

A quick way to check if a number is a perfect square: Observe the unit’s digit. Numbers ending in 2, 3, 7, or 8 are never perfect squares. Vedantu teachers use mnemonic devices and tables for rapid recall in live sessions.


We explored Squares and Square Roots—from definition, formulas, tables, mental math tricks, frequent errors, and cross-topic connections. Keep practicing using Vedantu’s worksheets and live classes to become confident and fast in these calculations.


Looking for more tools and practice? Try these helpful Vedantu resources:

FAQs on Understanding Squares and Square Roots in Maths

1. What is a square number in Maths?

A square number is a number obtained by multiplying an integer by itself. In other words, it is of the form n × n = n².

  • Examples: 1² = 1, 2² = 4, 3² = 9, 4² = 16
  • So, 4, 9, 16, 25 are all square numbers.
  • Square numbers are also called perfect squares.

2. What is the square root of a number?

The square root of a number is a value which, when multiplied by itself, gives the original number. It is written using the symbol .

  • Example: √25 = 5 because 5 × 5 = 25.
  • Example: √49 = 7 because 7 × 7 = 49.
  • If a number is not a perfect square, its square root is not a whole number.

3. How do you find the square of a number?

To find the square of a number, multiply the number by itself. The formula is n² = n × n.

  • Step 1: Take the number.
  • Step 2: Multiply it by itself.
  • Example: 8² = 8 × 8 = 64.
This method works for whole numbers, fractions, and decimals.

4. How do you find the square root of a perfect square?

To find the square root of a perfect square, identify the number that multiplies by itself to give the original number.

  • Example: √36 = ?
  • Since 6 × 6 = 36, √36 = 6.
  • You can also use prime factorization or memorized square tables.
Perfect squares have whole number square roots.

5. What is the difference between a square and a square root?

A square is the result of multiplying a number by itself, while a square root is the number that produces the original number when squared.

  • Square: 7² = 49
  • Square root: √49 = 7
  • Squaring increases the value (for numbers greater than 1), while taking the square root reduces it.

6. What are the first 10 square numbers?

The first 10 square numbers are the squares of natural numbers from 1 to 10.

  • 1² = 1
  • 2² = 4
  • 3² = 9
  • 4² = 16
  • 5² = 25
  • 6² = 36
  • 7² = 49
  • 8² = 64
  • 9² = 81
  • 10² = 100

7. How do you find the square root using prime factorization?

To find the square root using prime factorization, express the number as a product of prime factors and group them in pairs.

  • Example: Find √144.
  • Step 1: 144 = 2 × 2 × 2 × 2 × 3 × 3
  • Step 2: Pair the factors: (2 × 2)(2 × 2)(3 × 3)
  • Step 3: Take one number from each pair: 2 × 2 × 3 = 12
  • So, √144 = 12.

8. Why is the square root of a negative number not a real number?

The square root of a negative number is not a real number because no real number multiplied by itself gives a negative result.

  • Positive × Positive = Positive
  • Negative × Negative = Positive
  • So, there is no real number whose square is −9.
In advanced Maths, √(−9) = 3i, which is an imaginary number.

9. What is the square root symbol called?

The square root symbol is called the radical sign. It represents the operation of finding a square root.

  • Example: √16 = 4
  • The number inside the symbol is called the radicand.
  • The symbol can also represent cube roots and higher roots with an index.

10. Can you give an example of finding the square root of a decimal?

Yes, you can find the square root of a decimal by converting it into a fraction or using known square roots.

  • Example: √0.25
  • Step 1: 0.25 = 25/100
  • Step 2: √(25/100) = √25 / √100
  • Step 3: = 5/10 = 0.5
So, √0.25 = 0.5.