91321 divided by 72 
The aim is to understand the frequency of 72 in 91321.

Step 1:
9 divided by 72 is 0 with a remainder of 9.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtracting 0 from 9 leaves us with 9.
Append the next digit (1) from the dividend to 9 and continue with: 91 / 72

Let's proceed to step 2:
The number 72 fits into 91 1 times, leaving a remainder of 19.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
Deduct 72 from 91 and we're left with 19.
Grab the next digit (3) from the dividend, add it to 19, then carry on: 193 / 72

Advancing to step 3:
If we divide 193 by 72, we get 2 and a remainder of 49.
The next digit of our result is 2. 
Result so far: 12.0
The remainder is 49 after subtracting 144 from 193.
Fetch the next digit (2) from the dividend, attach it to 49 and continue: 492 / 72

Going ahead to step 4:
492 divided by 72 is 6 with a remainder of 60.
Record the quotient 6 as the next digit in the result. 
Result so far: 126.0
Deduct 432 from 492 and we're left with 60.
Append the next digit (1) from the dividend to 60 and continue with: 601 / 72

On to step 5:
72 can be fit into 601 8 times, resulting in a remainder of 25.
The number 8 becomes the next digit in our result. 
Result so far: 1268.0
The remainder is 25 after subtracting 576 from 601.
Since there are no more digits in the dividend, we add a zero to the remainder making it 250, and continue the process.

Going ahead to step 6:
72 can be fit into 250 3 times, resulting in a remainder of 34.
Record the quotient 3 as the next digit in the result. 
Result so far: 1268.3
Subtracting 216 from 250 leaves us with 34.
Since there are no more digits in the dividend, we add a zero to the remainder making it 340, and continue the process.

Advancing to step 7:
340 divided by 72 is 4 with a remainder of 52.
The number 4 becomes the next digit in our result. 
Result so far: 1268.34
Deduct 288 from 340 and we're left with 52.
Since there are no more digits in the dividend, we add a zero to the remainder making it 520, and continue the process.

Let's proceed to step 8:
72 can be fit into 520 7 times, resulting in a remainder of 16.
Put 7 as the next digit of the answer. 
Result so far: 1268.347
Subtracting 504 from 520 leaves us with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Let's proceed to step 9:
72 goes into 160 2 times with a remainder of 16.
The next digit of our result is 2. 
Result so far: 1268.3472
Subtract 144 from 160 to get 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Step 10:
72 can be fit into 160 2 times, resulting in a remainder of 16.
Use 2 as the next digit of our solution. 
Result so far: 1268.34722
Subtract 144 from 160 to get 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

The quotient of the division is 1268.34722, and the remainder is 1.6e-05.