We look at the division of 921631 by 72 
The aim is to understand the frequency of 72 in 921631.

Going ahead to step 1:
72 goes into 9 0 times with a remainder of 9.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we subtract 0 from 9, we get 9.
Bring next digit (2) of the dividend behind the 9 and repeat the process: 92 / 72

Advancing to step 2:
72 can be fit into 92 1 times, resulting in a remainder of 20.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
If we subtract 72 from 92, we get 20.
Take the next digit (1) from the dividend and append it to 20, then repeat: 201 / 72

Going ahead to step 3:
The number 72 fits into 201 2 times, leaving a remainder of 57.
Write down 2 as next digit of the result. 
Result so far: 12.0
Deduct 144 from 201 and we're left with 57.
Grab the next digit (6) from the dividend, add it to 57, then carry on: 576 / 72

Moving on to step 4:
The number 72 fits into 576 8 times, leaving a remainder of 0.
The number 8 becomes the next digit in our result. 
Result so far: 128.0
If we subtract 576 from 576, we get 0.
Fetch the next digit (3) from the dividend, attach it to 0 and continue: 3 / 72

Advancing to step 5:
The number 72 fits into 3 0 times, leaving a remainder of 3.
Write down 0 as next digit of the result. 
Result so far: 1280.0
Subtracting 0 from 3 leaves us with 3.
Bring next digit (1) of the dividend behind the 3 and repeat the process: 31 / 72

Step 6:
If we divide 31 by 72, we get 0 and a remainder of 31.
Record the quotient 0 as the next digit in the result. 
Result so far: 12800.0
If we take 0 away from 31, we end up with 31.
Since there are no more digits in the dividend, we add a zero to the remainder making it 310, and continue the process.

Step 7:
When dividing 310 by 72, we get 4 with a remainder of 22.
Record the quotient 4 as the next digit in the result. 
Result so far: 12800.4
Deduct 288 from 310 and we're left with 22.
Since there are no more digits in the dividend, we add a zero to the remainder making it 220, and continue the process.

Moving on to step 8:
When dividing 220 by 72, we get 3 with a remainder of 4.
Record the quotient 3 as the next digit in the result. 
Result so far: 12800.43
The remainder is 4 after subtracting 216 from 220.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Step 9:
72 goes into 40 0 times with a remainder of 40.
Record the quotient 0 as the next digit in the result. 
Result so far: 12800.43
Subtracting 0 from 40 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.

On to step 10:
If we divide 400 by 72, we get 5 and a remainder of 40.
Write down 5 as next digit of the result. 
Result so far: 12800.4305
The remainder is 40 after subtracting 360 from 400.
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 11:
72 goes into 400 5 times with a remainder of 40.
The number 5 becomes the next digit in our result. 
Result so far: 12800.43055
If we subtract 360 from 400, we get 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

After the division, we end up with 12800.43055 and a remainder of 4e-05.