We're dividing 120543 by 1 
The aim is to understand the frequency of 1 in 120543.

Advancing to step 1:
1 goes into 1 1 times with a remainder of 0.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
If we subtract 1 from 1, we get 0.
Append the next digit (2) from the dividend to 0 and continue with: 2 / 1

Going ahead to step 2:
1 can be fit into 2 2 times, resulting in a remainder of 0.
Put 2 as the next digit of the answer. 
Result so far: 12.0
The remainder is 0 after subtracting 2 from 2.
Take the next digit (0) from the dividend and append it to 0, then repeat: 0 / 1

Going ahead to step 3:
The number 1 fits into 0 0 times, leaving a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 120.0
If we take 0 away from 0, we end up with 0.
Append the next digit (5) from the dividend to 0 and continue with: 5 / 1

Going ahead to step 4:
5 divided by 1 is 5 with a remainder of 0.
The number 5 becomes the next digit in our result. 
Result so far: 1205.0
Deduct 5 from 5 and we're left with 0.
Fetch the next digit (4) from the dividend, attach it to 0 and continue: 4 / 1

Advancing to step 5:
1 goes into 4 4 times with a remainder of 0.
The next digit of our result is 4. 
Result so far: 12054.0
If we take 4 away from 4, we end up with 0.
Fetch the next digit (3) from the dividend, attach it to 0 and continue: 3 / 1

Advancing to step 6:
1 can be fit into 3 3 times, resulting in a remainder of 0.
Write down 3 as next digit of the result. 
Result so far: 120543.0
Deduct 3 from 3 and we're left 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.

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: 120543.0
Subtract 0 from 0 to 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.

On 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: 120543.0
Subtract 0 from 0 to 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.

The quotient of the division is 120543.0, and the remainder is 0.0.