753399 ÷ 1 
The aim is to understand the frequency of 1 in 753399.

Let's proceed to step 1:
1 goes into 7 7 times with a remainder of 0.
Use 7 as the next digit of our solution. 
Result so far: 7.0
The remainder is 0 after subtracting 7 from 7.
Bring next digit (5) of the dividend behind the 0 and repeat the process: 5 / 1

Step 2:
When dividing 5 by 1, we get 5 with a remainder of 0.
Record the quotient 5 as the next digit in the result. 
Result so far: 75.0
If we subtract 5 from 5, we get 0.
Bring next digit (3) of the dividend behind the 0 and repeat the process: 3 / 1

Let's proceed to step 3:
The number 1 fits into 3 3 times, leaving a remainder of 0.
Put 3 as the next digit of the answer. 
Result so far: 753.0
If we subtract 3 from 3, we get 0.
Fetch the next digit (3) from the dividend, attach it to 0 and continue: 3 / 1

Advancing to step 4:
3 divided by 1 is 3 with a remainder of 0.
The next digit of our result is 3. 
Result so far: 7533.0
Subtract 3 from 3 to get 0.
Append the next digit (9) from the dividend to 0 and continue with: 9 / 1

Going ahead to step 5:
The number 1 fits into 9 9 times, leaving a remainder of 0.
Put 9 as the next digit of the answer. 
Result so far: 75339.0
Deduct 9 from 9 and we're left with 0.
Include the next digit (9) from the dividend after 0, then repeat: 9 / 1

Step 6:
9 divided by 1 is 9 with a remainder of 0.
Record the quotient 9 as the next digit in the result. 
Result so far: 753399.0
If we subtract 9 from 9, we get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Moving on to step 7:
If we divide 0 by 1, we get 0 and a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 753399.0
The remainder is 0 after subtracting 0 from 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Going ahead to step 8:
1 goes into 0 0 times with a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 753399.0
Subtracting 0 from 0 leaves us with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

After the division, we end up with 753399.0 and a remainder of 0.0.