Theory:

In our earlier classes, we learned about power and exponent. Now, let us know about square and square numbers.
 
Look at the below pattern carefully.
 
dot_gif.gif
 
In the above pattern:
 
The first picture has \(1\) row and \(1\) column.
 
The second picture has \(2\) rows and \(2\) columns.
 
The third picture has \(3\) rows and \(3\) columns.
 
The fourth picture has \(4\) rows and \(4\) columns.
 
\(1 \times 1 = 1^2 = 1\)
 
\(2 \times 2 = 2^2 = 4\)
 
\(3 \times 3 = 3^2 = 9\)
 
\(4 \times 4 = 4^2 = 16\)
 
Here, we multiply the number by itself, and we obtained a square of that number.
 
The numbers \(1\), \(4\), \(9\) and \(16\) are called square numbers.
If a natural number \((m)\) is expressed as a power of \(2\), then the number \((m)\) is called a square number. That is \(m = n^2\). A square number is also called a perfect number.
Square_1.png
  
Important!
When we multiply a number by itself, we obtained a square of that number.