We're dividing 25085170 by 399 
We want to figure out the number of times 25085170 can be divided by 399.

Step 1:
399 goes into 2 0 times with a remainder of 2.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 2 after subtracting 0 from 2.
Fetch the next digit (5) from the dividend, attach it to 2 and continue: 25 / 399

Step 2:
25 divided by 399 is 0 with a remainder of 25.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 25 and we're left with 25.
Fetch the next digit (0) from the dividend, attach it to 25 and continue: 250 / 399

Advancing to step 3:
399 goes into 250 0 times with a remainder of 250.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 250, we get 250.
Take the next digit (8) from the dividend and append it to 250, then repeat: 2508 / 399

Let's proceed to step 4:
The number 399 fits into 2508 6 times, leaving a remainder of 114.
The number 6 becomes the next digit in our result. 
Result so far: 6.0
Subtracting 2394 from 2508 leaves us with 114.
Fetch the next digit (5) from the dividend, attach it to 114 and continue: 1145 / 399

On to step 5:
399 goes into 1145 2 times with a remainder of 347.
Write down 2 as next digit of the result. 
Result so far: 62.0
If we take 798 away from 1145, we end up with 347.
Bring next digit (1) of the dividend behind the 347 and repeat the process: 3471 / 399

On to step 6:
3471 divided by 399 is 8 with a remainder of 279.
Put 8 as the next digit of the answer. 
Result so far: 628.0
If we take 3192 away from 3471, we end up with 279.
Append the next digit (7) from the dividend to 279 and continue with: 2797 / 399

Advancing to step 7:
399 goes into 2797 7 times with a remainder of 4.
The next digit of our result is 7. 
Result so far: 6287.0
Deduct 2793 from 2797 and we're left with 4.
Take the next digit (0) from the dividend and append it to 4, then repeat: 40 / 399

Going ahead to step 8:
The number 399 fits into 40 0 times, leaving a remainder of 40.
The number 0 becomes the next digit in our result. 
Result so far: 62870.0
The remainder is 40 after subtracting 0 from 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Going ahead to step 9:
When dividing 400 by 399, we get 1 with a remainder of 1.
The number 1 becomes the next digit in our result. 
Result so far: 62870.1
Subtract 399 from 400 to get 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Moving on to step 10:
399 can be fit into 10 0 times, resulting in a remainder of 10.
The next digit of our result is 0. 
Result so far: 62870.1
The remainder is 10 after subtracting 0 from 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 11:
The number 399 fits into 100 0 times, leaving a remainder of 100.
The number 0 becomes the next digit in our result. 
Result so far: 62870.1
If we subtract 0 from 100, we get 100.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1000, and continue the process.

The final result is 62870.1 with a remainder of 0.01.