We're dividing 4353390 by 603 
The aim is to understand the frequency of 603 in 4353390.

Moving on to step 1:
When dividing 4 by 603, we get 0 with a remainder of 4.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtracting 0 from 4 leaves us with 4.
Take the next digit (3) from the dividend and append it to 4, then repeat: 43 / 603

Let's proceed to step 2:
603 goes into 43 0 times with a remainder of 43.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 43 to get 43.
Include the next digit (5) from the dividend after 43, then repeat: 435 / 603

Moving on to step 3:
435 divided by 603 is 0 with a remainder of 435.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 435 to get 435.
Take the next digit (3) from the dividend and append it to 435, then repeat: 4353 / 603

Moving on to step 4:
The number 603 fits into 4353 7 times, leaving a remainder of 132.
The number 7 becomes the next digit in our result. 
Result so far: 7.0
The remainder is 132 after subtracting 4221 from 4353.
Fetch the next digit (3) from the dividend, attach it to 132 and continue: 1323 / 603

On to step 5:
1323 divided by 603 is 2 with a remainder of 117.
The next digit of our result is 2. 
Result so far: 72.0
Subtracting 1206 from 1323 leaves us with 117.
Fetch the next digit (9) from the dividend, attach it to 117 and continue: 1179 / 603

Moving on to step 6:
603 can be fit into 1179 1 times, resulting in a remainder of 576.
Write down 1 as next digit of the result. 
Result so far: 721.0
If we take 603 away from 1179, we end up with 576.
Take the next digit (0) from the dividend and append it to 576, then repeat: 5760 / 603

On to step 7:
5760 divided by 603 is 9 with a remainder of 333.
Use 9 as the next digit of our solution. 
Result so far: 7219.0
Deduct 5427 from 5760 and we're left with 333.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3330, and continue the process.

Moving on to step 8:
When dividing 3330 by 603, we get 5 with a remainder of 315.
Put 5 as the next digit of the answer. 
Result so far: 7219.5
If we subtract 3015 from 3330, we get 315.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3150, and continue the process.

Advancing to step 9:
When dividing 3150 by 603, we get 5 with a remainder of 135.
The next digit of our result is 5. 
Result so far: 7219.55
If we take 3015 away from 3150, we end up with 135.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1350, and continue the process.

The final result is 7219.55 with a remainder of 0.135.