We look at the division of 399403 by 75 
Let's see how many times 75 fits into 399403.

Let's proceed to step 1:
If we divide 3 by 75, we get 0 and a remainder of 3.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we subtract 0 from 3, we get 3.
Take the next digit (9) from the dividend and append it to 3, then repeat: 39 / 75

On to step 2:
The number 75 fits into 39 0 times, leaving a remainder of 39.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 39 and we're left with 39.
Bring next digit (9) of the dividend behind the 39 and repeat the process: 399 / 75

Going ahead to step 3:
75 goes into 399 5 times with a remainder of 24.
The next digit of our result is 5. 
Result so far: 5.0
If we take 375 away from 399, we end up with 24.
Take the next digit (4) from the dividend and append it to 24, then repeat: 244 / 75

Step 4:
If we divide 244 by 75, we get 3 and a remainder of 19.
Write down 3 as next digit of the result. 
Result so far: 53.0
Subtracting 225 from 244 leaves us with 19.
Append the next digit (0) from the dividend to 19 and continue with: 190 / 75

Step 5:
If we divide 190 by 75, we get 2 and a remainder of 40.
The number 2 becomes the next digit in our result. 
Result so far: 532.0
Subtract 150 from 190 to get 40.
Bring next digit (3) of the dividend behind the 40 and repeat the process: 403 / 75

Advancing to step 6:
75 can be fit into 403 5 times, resulting in a remainder of 28.
The next digit of our result is 5. 
Result so far: 5325.0
Subtracting 375 from 403 leaves us with 28.
Since there are no more digits in the dividend, we add a zero to the remainder making it 280, and continue the process.

On to step 7:
If we divide 280 by 75, we get 3 and a remainder of 55.
The number 3 becomes the next digit in our result. 
Result so far: 5325.3
If we take 225 away from 280, we end up with 55.
Since there are no more digits in the dividend, we add a zero to the remainder making it 550, and continue the process.

Moving on to step 8:
75 goes into 550 7 times with a remainder of 25.
Put 7 as the next digit of the answer. 
Result so far: 5325.37
Subtract 525 from 550 to get 25.
Since there are no more digits in the dividend, we add a zero to the remainder making it 250, and continue the process.

Advancing to step 9:
If we divide 250 by 75, we get 3 and a remainder of 25.
Record the quotient 3 as the next digit in the result. 
Result so far: 5325.373
Subtract 225 from 250 to get 25.
Since there are no more digits in the dividend, we add a zero to the remainder making it 250, and continue the process.

Advancing to step 10:
75 can be fit into 250 3 times, resulting in a remainder of 25.
Write down 3 as next digit of the result. 
Result so far: 5325.3733
If we subtract 225 from 250, we get 25.
Since there are no more digits in the dividend, we add a zero to the remainder making it 250, and continue the process.

Our division results in 5325.3733 with a remaining 0.00025.