We look at the division of 8603399 by 431 
Let's see how many times 431 fits into 8603399.

Moving on to step 1:
8 divided by 431 is 0 with a remainder of 8.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 8 to get 8.
Append the next digit (6) from the dividend to 8 and continue with: 86 / 431

Let's proceed to step 2:
The number 431 fits into 86 0 times, leaving a remainder of 86.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtract 0 from 86 to get 86.
Take the next digit (0) from the dividend and append it to 86, then repeat: 860 / 431

Moving on to step 3:
431 goes into 860 1 times with a remainder of 429.
Put 1 as the next digit of the answer. 
Result so far: 1.0
If we take 431 away from 860, we end up with 429.
Include the next digit (3) from the dividend after 429, then repeat: 4293 / 431

Let's proceed to step 4:
When dividing 4293 by 431, we get 9 with a remainder of 414.
The number 9 becomes the next digit in our result. 
Result so far: 19.0
Subtracting 3879 from 4293 leaves us with 414.
Grab the next digit (3) from the dividend, add it to 414, then carry on: 4143 / 431

Advancing to step 5:
The number 431 fits into 4143 9 times, leaving a remainder of 264.
Record the quotient 9 as the next digit in the result. 
Result so far: 199.0
If we take 3879 away from 4143, we end up with 264.
Bring next digit (9) of the dividend behind the 264 and repeat the process: 2649 / 431

Let's proceed to step 6:
431 goes into 2649 6 times with a remainder of 63.
Write down 6 as next digit of the result. 
Result so far: 1996.0
The remainder is 63 after subtracting 2586 from 2649.
Take the next digit (9) from the dividend and append it to 63, then repeat: 639 / 431

Let's proceed to step 7:
431 can be fit into 639 1 times, resulting in a remainder of 208.
The number 1 becomes the next digit in our result. 
Result so far: 19961.0
The remainder is 208 after subtracting 431 from 639.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2080, and continue the process.

Step 8:
431 goes into 2080 4 times with a remainder of 356.
Write down 4 as next digit of the result. 
Result so far: 19961.4
Subtracting 1724 from 2080 leaves us with 356.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3560, and continue the process.

Step 9:
The number 431 fits into 3560 8 times, leaving a remainder of 112.
Put 8 as the next digit of the answer. 
Result so far: 19961.48
If we subtract 3448 from 3560, we get 112.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1120, and continue the process.

Moving on to step 10:
If we divide 1120 by 431, we get 2 and a remainder of 258.
Put 2 as the next digit of the answer. 
Result so far: 19961.482
If we take 862 away from 1120, we end up with 258.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2580, and continue the process.

Let's proceed to step 11:
The number 431 fits into 2580 5 times, leaving a remainder of 425.
Put 5 as the next digit of the answer. 
Result so far: 19961.4825
Subtracting 2155 from 2580 leaves us with 425.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4250, and continue the process.

Moving on to step 12:
When dividing 4250 by 431, we get 9 with a remainder of 371.
The number 9 becomes the next digit in our result. 
Result so far: 19961.48259
Deduct 3879 from 4250 and we're left with 371.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3710, and continue the process.

Moving on to step 13:
3710 divided by 431 is 8 with a remainder of 262.
Use 8 as the next digit of our solution. 
Result so far: 19961.482598
Subtract 3448 from 3710 to get 262.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2620, and continue the process.

On to step 14:
When dividing 2620 by 431, we get 6 with a remainder of 34.
Use 6 as the next digit of our solution. 
Result so far: 19961.4825986
Subtract 2586 from 2620 to get 34.
Since there are no more digits in the dividend, we add a zero to the remainder making it 340, and continue the process.

Advancing to step 15:
When dividing 340 by 431, we get 0 with a remainder of 340.
Write down 0 as next digit of the result. 
Result so far: 19961.4825986
The remainder is 340 after subtracting 0 from 340.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3400, and continue the process.

The final outcome is 19961.4825986, with a leftover of 3.4e-07.