We look at the division of 20521229 by 603 
Let's see how many times 603 fits into 20521229.

Step 1:
603 goes into 2 0 times with a remainder of 2.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtract 0 from 2 to get 2.
Include the next digit (0) from the dividend after 2, then repeat: 20 / 603

Moving on to step 2:
20 divided by 603 is 0 with a remainder of 20.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 20 to get 20.
Fetch the next digit (5) from the dividend, attach it to 20 and continue: 205 / 603

Moving on to step 3:
The number 603 fits into 205 0 times, leaving a remainder of 205.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
The remainder is 205 after subtracting 0 from 205.
Take the next digit (2) from the dividend and append it to 205, then repeat: 2052 / 603

On to step 4:
If we divide 2052 by 603, we get 3 and a remainder of 243.
Put 3 as the next digit of the answer. 
Result so far: 3.0
The remainder is 243 after subtracting 1809 from 2052.
Fetch the next digit (1) from the dividend, attach it to 243 and continue: 2431 / 603

Advancing to step 5:
603 goes into 2431 4 times with a remainder of 19.
Use 4 as the next digit of our solution. 
Result so far: 34.0
If we subtract 2412 from 2431, we get 19.
Take the next digit (2) from the dividend and append it to 19, then repeat: 192 / 603

Step 6:
If we divide 192 by 603, we get 0 and a remainder of 192.
Write down 0 as next digit of the result. 
Result so far: 340.0
Subtracting 0 from 192 leaves us with 192.
Take the next digit (2) from the dividend and append it to 192, then repeat: 1922 / 603

On to step 7:
When dividing 1922 by 603, we get 3 with a remainder of 113.
Record the quotient 3 as the next digit in the result. 
Result so far: 3403.0
Subtract 1809 from 1922 to get 113.
Bring next digit (9) of the dividend behind the 113 and repeat the process: 1139 / 603

On to step 8:
The number 603 fits into 1139 1 times, leaving a remainder of 536.
The number 1 becomes the next digit in our result. 
Result so far: 34031.0
Deduct 603 from 1139 and we're left with 536.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5360, and continue the process.

Advancing to step 9:
The number 603 fits into 5360 8 times, leaving a remainder of 536.
Record the quotient 8 as the next digit in the result. 
Result so far: 34031.8
Subtracting 4824 from 5360 leaves us with 536.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5360, and continue the process.

Let's proceed to step 10:
When dividing 5360 by 603, we get 8 with a remainder of 536.
Use 8 as the next digit of our solution. 
Result so far: 34031.88
If we subtract 4824 from 5360, we get 536.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5360, and continue the process.

The quotient of the division is 34031.88, and the remainder is 0.536.