We're dividing 15599791 by 603 
Our goal is to divide 15599791 by 603.

Going ahead to step 1:
603 goes into 1 0 times with a remainder of 1.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 1 after subtracting 0 from 1.
Bring next digit (5) of the dividend behind the 1 and repeat the process: 15 / 603

On to step 2:
If we divide 15 by 603, we get 0 and a remainder of 15.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtracting 0 from 15 leaves us with 15.
Grab the next digit (5) from the dividend, add it to 15, then carry on: 155 / 603

Let's proceed to step 3:
If we divide 155 by 603, we get 0 and a remainder of 155.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 155 after subtracting 0 from 155.
Grab the next digit (9) from the dividend, add it to 155, then carry on: 1559 / 603

Going ahead to step 4:
If we divide 1559 by 603, we get 2 and a remainder of 353.
Use 2 as the next digit of our solution. 
Result so far: 2.0
The remainder is 353 after subtracting 1206 from 1559.
Take the next digit (9) from the dividend and append it to 353, then repeat: 3539 / 603

Let's proceed to step 5:
603 goes into 3539 5 times with a remainder of 524.
Record the quotient 5 as the next digit in the result. 
Result so far: 25.0
If we take 3015 away from 3539, we end up with 524.
Bring next digit (7) of the dividend behind the 524 and repeat the process: 5247 / 603

On to step 6:
If we divide 5247 by 603, we get 8 and a remainder of 423.
Put 8 as the next digit of the answer. 
Result so far: 258.0
The remainder is 423 after subtracting 4824 from 5247.
Append the next digit (9) from the dividend to 423 and continue with: 4239 / 603

On to step 7:
4239 divided by 603 is 7 with a remainder of 18.
Put 7 as the next digit of the answer. 
Result so far: 2587.0
The remainder is 18 after subtracting 4221 from 4239.
Take the next digit (1) from the dividend and append it to 18, then repeat: 181 / 603

On to step 8:
181 divided by 603 is 0 with a remainder of 181.
Put 0 as the next digit of the answer. 
Result so far: 25870.0
Deduct 0 from 181 and we're left with 181.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1810, and continue the process.

On to step 9:
603 can be fit into 1810 3 times, resulting in a remainder of 1.
Put 3 as the next digit of the answer. 
Result so far: 25870.3
Subtracting 1809 from 1810 leaves us with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Step 10:
If we divide 10 by 603, we get 0 and a remainder of 10.
The number 0 becomes the next digit in our result. 
Result so far: 25870.3
Subtract 0 from 10 to get 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Going ahead to step 11:
100 divided by 603 is 0 with a remainder of 100.
The number 0 becomes the next digit in our result. 
Result so far: 25870.3
Deduct 0 from 100 and we're left with 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 outcome is 25870.3, with a leftover of 0.01.