We divide 53903623 by 999
The aim is to understand the frequency of 999 in 53903623.

Going ahead to step 1:
999 can be fit into 5 0 times, resulting in a remainder of 5.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
The remainder is 5 after subtracting 0 from 5.
Include the next digit (3) from the dividend after 5, then repeat: 53 / 999

Advancing to step 2:
999 can be fit into 53 0 times, resulting in a remainder of 53.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Deduct 0 from 53 and we're left with 53.
Include the next digit (9) from the dividend after 53, then repeat: 539 / 999

On to step 3:
999 can be fit into 539 0 times, resulting in a remainder of 539.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtracting 0 from 539 leaves us with 539.
Include the next digit (0) from the dividend after 539, then repeat: 5390 / 999

Step 4:
5390 divided by 999 is 5 with a remainder of 395.
Write down 5 as next digit of the result. 
Result so far: 5.0
Subtracting 4995 from 5390 leaves us with 395.
Bring next digit (3) of the dividend behind the 395 and repeat the process: 3953 / 999

On to step 5:
3953 divided by 999 is 3 with a remainder of 956.
Use 3 as the next digit of our solution. 
Result so far: 53.0
Subtracting 2997 from 3953 leaves us with 956.
Bring next digit (6) of the dividend behind the 956 and repeat the process: 9566 / 999

Let's proceed to step 6:
When dividing 9566 by 999, we get 9 with a remainder of 575.
Record the quotient 9 as the next digit in the result. 
Result so far: 539.0
Subtracting 8991 from 9566 leaves us with 575.
Bring next digit (2) of the dividend behind the 575 and repeat the process: 5752 / 999

Moving on to step 7:
999 can be fit into 5752 5 times, resulting in a remainder of 757.
Use 5 as the next digit of our solution. 
Result so far: 5395.0
The remainder is 757 after subtracting 4995 from 5752.
Fetch the next digit (3) from the dividend, attach it to 757 and continue: 7573 / 999

On to step 8:
When dividing 7573 by 999, we get 7 with a remainder of 580.
The number 7 becomes the next digit in our result. 
Result so far: 53957.0
Subtracting 6993 from 7573 leaves us with 580.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5800, and continue the process.

On to step 9:
999 can be fit into 5800 5 times, resulting in a remainder of 805.
Write down 5 as next digit of the result. 
Result so far: 53957.5
If we subtract 4995 from 5800, we get 805.
Since there are no more digits in the dividend, we add a zero to the remainder making it 8050, and continue the process.

Let's proceed to step 10:
If we divide 8050 by 999, we get 8 and a remainder of 58.
Put 8 as the next digit of the answer. 
Result so far: 53957.58
The remainder is 58 after subtracting 7992 from 8050.
Since there are no more digits in the dividend, we add a zero to the remainder making it 580, and continue the process.

Advancing to step 11:
If we divide 580 by 999, we get 0 and a remainder of 580.
The number 0 becomes the next digit in our result. 
Result so far: 53957.58
If we take 0 away from 580, we end up with 580.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5800, and continue the process.

Let's proceed to step 12:
The number 999 fits into 5800 5 times, leaving a remainder of 805.
The number 5 becomes the next digit in our result. 
Result so far: 53957.5805
If we take 4995 away from 5800, we end up with 805.
Since there are no more digits in the dividend, we add a zero to the remainder making it 8050, and continue the process.

Going ahead to step 13:
999 goes into 8050 8 times with a remainder of 58.
The number 8 becomes the next digit in our result. 
Result so far: 53957.58058
The remainder is 58 after subtracting 7992 from 8050.
Since there are no more digits in the dividend, we add a zero to the remainder making it 580, and continue the process.

Going ahead to step 14:
When dividing 580 by 999, we get 0 with a remainder of 580.
Use 0 as the next digit of our solution. 
Result so far: 53957.58058
If we subtract 0 from 580, we get 580.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5800, and continue the process.

Moving on to step 15:
The number 999 fits into 5800 5 times, leaving a remainder of 805.
Put 5 as the next digit of the answer. 
Result so far: 53957.5805805
If we take 4995 away from 5800, we end up with 805.
Since there are no more digits in the dividend, we add a zero to the remainder making it 8050, and continue the process.

Advancing to step 16:
8050 divided by 999 is 8 with a remainder of 58.
The number 8 becomes the next digit in our result. 
Result so far: 53957.58058058
Subtracting 7992 from 8050 leaves us with 58.
Since there are no more digits in the dividend, we add a zero to the remainder making it 580, and continue the process.

The final result is 53957.58058058 with a remainder of 5.8e-08.