91549 ÷ 75 
The aim is to understand the frequency of 75 in 91549.

On to step 1:
When dividing 9 by 75, we get 0 with a remainder of 9.
The next digit of our result is 0. 
Result so far: 0.0
If we subtract 0 from 9, we get 9.
Take the next digit (1) from the dividend and append it to 9, then repeat: 91 / 75

Let's proceed to step 2:
75 can be fit into 91 1 times, resulting in a remainder of 16.
Put 1 as the next digit of the answer. 
Result so far: 1.0
The remainder is 16 after subtracting 75 from 91.
Grab the next digit (5) from the dividend, add it to 16, then carry on: 165 / 75

On to step 3:
75 goes into 165 2 times with a remainder of 15.
The next digit of our result is 2. 
Result so far: 12.0
If we subtract 150 from 165, we get 15.
Fetch the next digit (4) from the dividend, attach it to 15 and continue: 154 / 75

Let's proceed to step 4:
When dividing 154 by 75, we get 2 with a remainder of 4.
Record the quotient 2 as the next digit in the result. 
Result so far: 122.0
Subtract 150 from 154 to get 4.
Append the next digit (9) from the dividend to 4 and continue with: 49 / 75

Moving on to step 5:
The number 75 fits into 49 0 times, leaving a remainder of 49.
Record the quotient 0 as the next digit in the result. 
Result so far: 1220.0
Deduct 0 from 49 and we're left with 49.
Since there are no more digits in the dividend, we add a zero to the remainder making it 490, and continue the process.

Moving on to step 6:
75 goes into 490 6 times with a remainder of 40.
Use 6 as the next digit of our solution. 
Result so far: 1220.6
Subtracting 450 from 490 leaves us with 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Let's proceed to step 7:
When dividing 400 by 75, we get 5 with a remainder of 25.
Write down 5 as next digit of the result. 
Result so far: 1220.65
If we take 375 away from 400, we end up with 25.
Since there are no more digits in the dividend, we add a zero to the remainder making it 250, and continue the process.

Moving on to step 8:
75 goes into 250 3 times with a remainder of 25.
Write down 3 as next digit of the result. 
Result so far: 1220.653
If we take 225 away from 250, we end up with 25.
Since there are no more digits in the dividend, we add a zero to the remainder making it 250, and continue the process.

On to step 9:
75 can be fit into 250 3 times, resulting in a remainder of 25.
Put 3 as the next digit of the answer. 
Result so far: 1220.6533
The remainder is 25 after subtracting 225 from 250.
Since there are no more digits in the dividend, we add a zero to the remainder making it 250, and continue the process.

The quotient of the division is 1220.6533, and the remainder is 0.00025.