# Introduction

**Squares :-**

Let us discuss what a square number is.

Consider a floor. We are going to place the tiles in the floor in such a way that number of tiles in both vertical and horizontal sides is equal.

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Â Number of tiles placed = 1 Â´ 1 = 1

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Number of tiles placed = 2 Â´ 2 = 4

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Number of tiles placed = 3 Â´ 3 = 9

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Number of tiles placed = 4 Â´ 4 = 16

If we proceed in this manner we get,

5 Â´ 5 = 25, 6 Â´ 6 = 36, 7 Â´ 7 = 49â€¦.

The numbers 4, 9, 16, 25, 36, 49â€¦â€¦ are called square numbers.

Square Number: A number that is the product of two equal numbers.

The numbers 1, 4, 9, 16 â€¦. are known as square numbers. They are also called as perfect square numbers.

Consider the number 65.

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Can we write it as a product of two equal numbers?

It canâ€™t be written as a product of two equal numbers.

So, it is not a perfect square number.