745209 ÷ 81 
The aim is to understand the frequency of 81 in 745209.

Advancing to step 1:
81 goes into 7 0 times with a remainder of 7.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we subtract 0 from 7, we get 7.
Grab the next digit (4) from the dividend, add it to 7, then carry on: 74 / 81

Advancing to step 2:
81 can be fit into 74 0 times, resulting in a remainder of 74.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtract 0 from 74 to get 74.
Grab the next digit (5) from the dividend, add it to 74, then carry on: 745 / 81

On to step 3:
81 can be fit into 745 9 times, resulting in a remainder of 16.
Use 9 as the next digit of our solution. 
Result so far: 9.0
The remainder is 16 after subtracting 729 from 745.
Take the next digit (2) from the dividend and append it to 16, then repeat: 162 / 81

Moving on to step 4:
When dividing 162 by 81, we get 2 with a remainder of 0.
Put 2 as the next digit of the answer. 
Result so far: 92.0
If we take 162 away from 162, we end up with 0.
Append the next digit (0) from the dividend to 0 and continue with: 0 / 81

Step 5:
When dividing 0 by 81, we get 0 with a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 920.0
If we subtract 0 from 0, we get 0.
Take the next digit (9) from the dividend and append it to 0, then repeat: 9 / 81

Moving on to step 6:
81 goes into 9 0 times with a remainder of 9.
Record the quotient 0 as the next digit in the result. 
Result so far: 9200.0
Subtract 0 from 9 to get 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Going ahead to step 7:
If we divide 90 by 81, we get 1 and a remainder of 9.
Record the quotient 1 as the next digit in the result. 
Result so far: 9200.1
Subtract 81 from 90 to get 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Step 8:
When dividing 90 by 81, we get 1 with a remainder of 9.
Write down 1 as next digit of the result. 
Result so far: 9200.11
Deduct 81 from 90 and we're left with 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Our division results in 9200.11 with a remaining 0.009.