Long Division
Below
is the process written out in full.
You will often see other versions, which are generally just a shortened version of the process below.
You can also see this done in Long Division Animation.
Let's see how it is done with:
 the number to be divided into is known as the dividend
 The number which divides the other number is known as the divisor
And here we go:
4 ÷ 25 = 0 remainder 4  The first digit of the dividend (4) is divided by the divisor. 

The whole number result is placed at the top. Any remainders are ignored at this point.  
25 × 0 = 0  The answer from the first operation is multiplied by the divisor. The result is placed under the number divided into.  
4 – 0 = 4  Now we subtract the bottom number from the top number.  
Bring down the next digit of the dividend.  
42 ÷ 25 = 1 remainder 17  Divide this number by the divisor.  
The whole number result is placed at the top. Any remainders are ignored at this point.  
25 × 1 = 25  The answer from the above operation is multiplied by the divisor. The result is placed under the last number divided into.  
42 – 25 = 17  Now we subtract the bottom number from the top number.  
Bring down the next digit of the dividend.  
175 ÷ 25 = 7 remainder 0  Divide this number by the divisor.  
The whole number result is placed at the top. Any remainders are ignored at this point.  
25 × 7 = 175  The answer from the above operation is multiplied by the divisor. The result is placed under the number divided into.  
175 – 175 = 0  Now we subtract the bottom number from the top number.  
There are no more digits to bring down. The answer must be 17 