We're dividing 639121 by 25 
We want to figure out the number of times 639121 can be divided by 25.

Let's proceed to step 1:
The number 25 fits into 6 0 times, leaving a remainder of 6.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we subtract 0 from 6, we get 6.
Grab the next digit (3) from the dividend, add it to 6, then carry on: 63 / 25

Advancing to step 2:
The number 25 fits into 63 2 times, leaving a remainder of 13.
Use 2 as the next digit of our solution. 
Result so far: 2.0
If we subtract 50 from 63, we get 13.
Include the next digit (9) from the dividend after 13, then repeat: 139 / 25

Going ahead to step 3:
The number 25 fits into 139 5 times, leaving a remainder of 14.
The number 5 becomes the next digit in our result. 
Result so far: 25.0
Subtracting 125 from 139 leaves us with 14.
Bring next digit (1) of the dividend behind the 14 and repeat the process: 141 / 25

Advancing to step 4:
141 divided by 25 is 5 with a remainder of 16.
The number 5 becomes the next digit in our result. 
Result so far: 255.0
If we subtract 125 from 141, we get 16.
Grab the next digit (2) from the dividend, add it to 16, then carry on: 162 / 25

Moving on to step 5:
162 divided by 25 is 6 with a remainder of 12.
Use 6 as the next digit of our solution. 
Result so far: 2556.0
Subtracting 150 from 162 leaves us with 12.
Grab the next digit (1) from the dividend, add it to 12, then carry on: 121 / 25

On to step 6:
25 can be fit into 121 4 times, resulting in a remainder of 21.
The number 4 becomes the next digit in our result. 
Result so far: 25564.0
Subtracting 100 from 121 leaves us with 21.
Since there are no more digits in the dividend, we add a zero to the remainder making it 210, and continue the process.

Moving on to step 7:
25 can be fit into 210 8 times, resulting in a remainder of 10.
Record the quotient 8 as the next digit in the result. 
Result so far: 25564.8
If we take 200 away from 210, we end up with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

On to step 8:
The number 25 fits into 100 4 times, leaving a remainder of 0.
The number 4 becomes the next digit in our result. 
Result so far: 25564.84
Subtract 100 from 100 to get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Advancing to step 9:
If we divide 0 by 25, we get 0 and a remainder of 0.
The next digit of our result is 0. 
Result so far: 25564.84
Subtracting 0 from 0 leaves us with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Going ahead to step 10:
If we divide 0 by 25, we get 0 and a remainder of 0.
The next digit of our result is 0. 
Result so far: 25564.84
If we take 0 away from 0, we end up with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

The final outcome is 25564.84, with a leftover of 0.0.