We look at the division of 25136821 by 631 
We want to divide 25136821 by 631.

Going ahead to step 1:
631 can be fit into 2 0 times, resulting in a remainder of 2.
The next digit of our result is 0. 
Result so far: 0.0
If we take 0 away from 2, we end up with 2.
Include the next digit (5) from the dividend after 2, then repeat: 25 / 631

Let's proceed to step 2:
The number 631 fits into 25 0 times, leaving a remainder of 25.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 25, we get 25.
Append the next digit (1) from the dividend to 25 and continue with: 251 / 631

Going ahead to step 3:
631 can be fit into 251 0 times, resulting in a remainder of 251.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 251 after subtracting 0 from 251.
Take the next digit (3) from the dividend and append it to 251, then repeat: 2513 / 631

Moving on to step 4:
631 goes into 2513 3 times with a remainder of 620.
Write down 3 as next digit of the result. 
Result so far: 3.0
If we take 1893 away from 2513, we end up with 620.
Append the next digit (6) from the dividend to 620 and continue with: 6206 / 631

Moving on to step 5:
631 goes into 6206 9 times with a remainder of 527.
Put 9 as the next digit of the answer. 
Result so far: 39.0
Deduct 5679 from 6206 and we're left with 527.
Grab the next digit (8) from the dividend, add it to 527, then carry on: 5278 / 631

Step 6:
631 can be fit into 5278 8 times, resulting in a remainder of 230.
Put 8 as the next digit of the answer. 
Result so far: 398.0
Subtract 5048 from 5278 to get 230.
Take the next digit (2) from the dividend and append it to 230, then repeat: 2302 / 631

Let's proceed to step 7:
631 goes into 2302 3 times with a remainder of 409.
Use 3 as the next digit of our solution. 
Result so far: 3983.0
Subtract 1893 from 2302 to get 409.
Take the next digit (1) from the dividend and append it to 409, then repeat: 4091 / 631

Let's proceed to step 8:
If we divide 4091 by 631, we get 6 and a remainder of 305.
Put 6 as the next digit of the answer. 
Result so far: 39836.0
If we take 3786 away from 4091, we end up with 305.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3050, and continue the process.

Let's proceed to step 9:
631 goes into 3050 4 times with a remainder of 526.
The number 4 becomes the next digit in our result. 
Result so far: 39836.4
Subtract 2524 from 3050 to get 526.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5260, and continue the process.

On to step 10:
When dividing 5260 by 631, we get 8 with a remainder of 212.
Use 8 as the next digit of our solution. 
Result so far: 39836.48
Subtracting 5048 from 5260 leaves us with 212.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2120, and continue the process.

Step 11:
When dividing 2120 by 631, we get 3 with a remainder of 227.
Write down 3 as next digit of the result. 
Result so far: 39836.483
The remainder is 227 after subtracting 1893 from 2120.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2270, and continue the process.

Going ahead to step 12:
631 goes into 2270 3 times with a remainder of 377.
The next digit of our result is 3. 
Result so far: 39836.4833
Subtracting 1893 from 2270 leaves us with 377.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3770, and continue the process.

The final result is 39836.4833 with a remainder of 0.00377.