We look at the division of 25171421 by 394 
Our goal is to divide 25171421 by 394.

Advancing to step 1:
394 goes into 2 0 times with a remainder of 2.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 2 after subtracting 0 from 2.
Grab the next digit (5) from the dividend, add it to 2, then carry on: 25 / 394

Let's proceed to step 2:
When dividing 25 by 394, we get 0 with a remainder of 25.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 25, we get 25.
Fetch the next digit (1) from the dividend, attach it to 25 and continue: 251 / 394

Step 3:
251 divided by 394 is 0 with a remainder of 251.
Write down 0 as next digit of the result. 
Result so far: 0.0
The remainder is 251 after subtracting 0 from 251.
Fetch the next digit (7) from the dividend, attach it to 251 and continue: 2517 / 394

Step 4:
If we divide 2517 by 394, we get 6 and a remainder of 153.
Write down 6 as next digit of the result. 
Result so far: 6.0
If we take 2364 away from 2517, we end up with 153.
Grab the next digit (1) from the dividend, add it to 153, then carry on: 1531 / 394

Let's proceed to step 5:
1531 divided by 394 is 3 with a remainder of 349.
Write down 3 as next digit of the result. 
Result so far: 63.0
If we subtract 1182 from 1531, we get 349.
Fetch the next digit (4) from the dividend, attach it to 349 and continue: 3494 / 394

Step 6:
394 can be fit into 3494 8 times, resulting in a remainder of 342.
The next digit of our result is 8. 
Result so far: 638.0
Deduct 3152 from 3494 and we're left with 342.
Bring next digit (2) of the dividend behind the 342 and repeat the process: 3422 / 394

Advancing to step 7:
394 can be fit into 3422 8 times, resulting in a remainder of 270.
The next digit of our result is 8. 
Result so far: 6388.0
Subtract 3152 from 3422 to get 270.
Include the next digit (1) from the dividend after 270, then repeat: 2701 / 394

Step 8:
394 goes into 2701 6 times with a remainder of 337.
Record the quotient 6 as the next digit in the result. 
Result so far: 63886.0
If we subtract 2364 from 2701, we get 337.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3370, and continue the process.

Going ahead to step 9:
394 goes into 3370 8 times with a remainder of 218.
Put 8 as the next digit of the answer. 
Result so far: 63886.8
Subtracting 3152 from 3370 leaves us with 218.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2180, and continue the process.

Step 10:
The number 394 fits into 2180 5 times, leaving a remainder of 210.
Put 5 as the next digit of the answer. 
Result so far: 63886.85
Subtract 1970 from 2180 to get 210.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2100, and continue the process.

Advancing to step 11:
394 goes into 2100 5 times with a remainder of 130.
Record the quotient 5 as the next digit in the result. 
Result so far: 63886.855
Subtract 1970 from 2100 to get 130.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1300, and continue the process.

The final outcome is 63886.855, with a leftover of 0.013.