The square root of 4 is denoted by √4, where symbol ‘√’ is the symbol of the square root. Number 4 is a perfect square. So it is easy to find the root of 4 and other such perfect numbers. Whereas in the case of non-perfect square number, to find its root value, we have to use the long division method.
The value of root 4 is equal to exactly 2. But the roots could be positive or negative or we can say there are always two roots for any given number. Hence, root 4 is equal to ±2 or +2 and -2 (positive 2 and negative 2). You can also find square root on a calculator. To calculate the square root of a number online click here Square root calculator.
Basically, a number when get multiplied by itself is called a square number. For example: 3 x 3 = 9 so 9 is a square number. You can see some more examples below:
- 16 = 4 x 4 = 42
 - 64 = 8 x 8 = 82
 - 49 = 7 x 7 = 72
 - 36 = 6 x 6 = 62
 
In this article, you will learn to find the root of 4. This topic is widely explained in Class 8 syllabus, where square and the square root of different numbers have been determined. Let us see some basics related to square root.
Also, read:
What is a perfect square?
A simple way to know if a number is a perfect square or not:
- If a number ends with 2, 3, 7, 8 at the unit place then it is not a perfect square
 - If a number is a perfect square, then it ends with 1, 4, 5, 6, 9 in the unit place but vice versa is not possible. For example, 25 is a perfect square, whereas 35 is not
 
What is the Square root of 4?
In mathematics, squaring a number is not difficult as the calculation is easy. To find the square root of a number is complicated as we need to find the original number that was squared. Let us consider an example: +5 and -5 are square roots of 25 because 52 = (-5)2 = 25. A non-negative real number has a unique non-negative square root. It is called principal square root denoted by √a. √ is called the radical symbol or radix and in this example, the principal square root of 25 is 5 which is denoted by √25 = 5, because 52 = 5 • 5 = 25 and 5 is non-negative. The number underneath the radical symbol is called the radicand. Here the radicand is 25.
Considering the above example, +2 and -2 are square roots of 4 because 22 = (-2)2 = 4. A non-negative real number has a unique non-negative square root. It is called principal square root denoted by √a. √ is called the radical symbol or radix and in this example, the principal square root of 4 is 2 which is denoted by √4 = 2 because 22 = 2 • 2 = 4 and 2 are non-negative. The number underneath the radical symbol is called the radicand. Here the radicand is 4. Here is a video for the shortcut method to find out the square root of a number.
Square root of 40
40 is the multiple of 4 and 10. As we already know, the root of 4 is equal to 2 but what about number 10. Since 10 is not a perfect square, thus we have to find the root of 10 using the long division method.
Hence, we can write,
Value of root 40 = √40 = √4 x √10 = 2 √10
Since, √10 = 3.162 [By long division method]
Hence, √40 = 2 x 3.162 = 6.324
Square root of 400
When number 4 is multiplied by 100 it results in 400, such as;
4 x 100 = 400
As you can see, both 4 and 100 are the perfect squares. Hence, it is easy to find the root value of 400. Therefore,
√400 = √4 x √100 = 2 x 10 = 20
Hence, 20 is the answer.
Video Lessons on Square Roots
Visualising square roots

Finding Square roots

Square Root From 1 to 50
Here is the list of the square root of numbers from 1 to 50. Student can use this table to do calculations.
| Number | Square Root Value | 
| 1 | 1 | 
| 2 | 1.414 | 
| 3 | 1.732 | 
| 4 | 2 | 
| 5 | 2.236 | 
| 6 | 2.449 | 
| 7 | 2.646 | 
| 8 | 2.828 | 
| 9 | 3 | 
| 10 | 3.162 | 
| 11 | 3.317 | 
| 12 | 3.464 | 
| 13 | 3.606 | 
| 14 | 3.742 | 
| 15 | 3.873 | 
| 16 | 4 | 
| 17 | 4.123 | 
| 18 | 4.243 | 
| 19 | 4.359 | 
| 20 | 4.472 | 
| 21 | 4.583 | 
| 22 | 4.69 | 
| 23 | 4.796 | 
| 24 | 4.899 | 
| 25 | 5 | 
| 26 | 5.099 | 
| 27 | 5.196 | 
| 28 | 5.292 | 
| 29 | 5.385 | 
| 30 | 5.477 | 
| 31 | 5.568 | 
| 32 | 5.657 | 
| 33 | 5.745 | 
| 34 | 5.831 | 
| 35 | 5.916 | 
| 36 | 6 | 
| 37 | 6.083 | 
| 38 | 6.164 | 
| 39 | 6.245 | 
| 40 | 6.325 | 
| 41 | 6.403 | 
| 42 | 6.481 | 
| 43 | 6.557 | 
| 44 | 6.633 | 
| 45 | 6.708 | 
| 46 | 6.782 | 
| 47 | 6.856 | 
| 48 | 6.928 | 
| 49 | 7 | 
| 50 | 7.071 | 
                        
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