We're dividing 903088 by 3 
The aim is to understand the frequency of 3 in 903088.

Let's proceed to step 1:
The number 3 fits into 9 3 times, leaving a remainder of 0.
The next digit of our result is 3. 
Result so far: 3.0
Subtract 9 from 9 to get 0.
Include the next digit (0) from the dividend after 0, then repeat: 0 / 3

On to step 2:
3 can be fit into 0 0 times, resulting in a remainder of 0.
Record the quotient 0 as the next digit in the result. 
Result so far: 30.0
Subtracting 0 from 0 leaves us with 0.
Include the next digit (3) from the dividend after 0, then repeat: 3 / 3

Advancing to step 3:
3 goes into 3 1 times with a remainder of 0.
Write down 1 as next digit of the result. 
Result so far: 301.0
Deduct 3 from 3 and we're left with 0.
Append the next digit (0) from the dividend to 0 and continue with: 0 / 3

Step 4:
3 can be fit into 0 0 times, resulting in a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 3010.0
Deduct 0 from 0 and we're left with 0.
Bring next digit (8) of the dividend behind the 0 and repeat the process: 8 / 3

Advancing to step 5:
When dividing 8 by 3, we get 2 with a remainder of 2.
The next digit of our result is 2. 
Result so far: 30102.0
If we subtract 6 from 8, we get 2.
Include the next digit (8) from the dividend after 2, then repeat: 28 / 3

On to step 6:
3 can be fit into 28 9 times, resulting in a remainder of 1.
The number 9 becomes the next digit in our result. 
Result so far: 301029.0
If we subtract 27 from 28, we get 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 7:
10 divided by 3 is 3 with a remainder of 1.
Write down 3 as next digit of the result. 
Result so far: 301029.3
Subtract 9 from 10 to get 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Moving on to step 8:
When dividing 10 by 3, we get 3 with a remainder of 1.
Write down 3 as next digit of the result. 
Result so far: 301029.33
Subtracting 9 from 10 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.

The final result is 301029.33 with a remainder of 0.001.