We look at the division of 87398 by 72 
The aim is to understand the frequency of 72 in 87398.

On to step 1:
If we divide 8 by 72, we get 0 and a remainder of 8.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we take 0 away from 8, we end up with 8.
Grab the next digit (7) from the dividend, add it to 8, then carry on: 87 / 72

On to step 2:
72 goes into 87 1 times with a remainder of 15.
Use 1 as the next digit of our solution. 
Result so far: 1.0
The remainder is 15 after subtracting 72 from 87.
Take the next digit (3) from the dividend and append it to 15, then repeat: 153 / 72

Moving on to step 3:
The number 72 fits into 153 2 times, leaving a remainder of 9.
The number 2 becomes the next digit in our result. 
Result so far: 12.0
Subtract 144 from 153 to get 9.
Append the next digit (9) from the dividend to 9 and continue with: 99 / 72

On to step 4:
The number 72 fits into 99 1 times, leaving a remainder of 27.
Record the quotient 1 as the next digit in the result. 
Result so far: 121.0
If we subtract 72 from 99, we get 27.
Bring next digit (8) of the dividend behind the 27 and repeat the process: 278 / 72

Advancing to step 5:
When dividing 278 by 72, we get 3 with a remainder of 62.
The number 3 becomes the next digit in our result. 
Result so far: 1213.0
Subtract 216 from 278 to get 62.
Since there are no more digits in the dividend, we add a zero to the remainder making it 620, and continue the process.

Going ahead to step 6:
When dividing 620 by 72, we get 8 with a remainder of 44.
Record the quotient 8 as the next digit in the result. 
Result so far: 1213.8
Subtracting 576 from 620 leaves us with 44.
Since there are no more digits in the dividend, we add a zero to the remainder making it 440, and continue the process.

On to step 7:
The number 72 fits into 440 6 times, leaving a remainder of 8.
Record the quotient 6 as the next digit in the result. 
Result so far: 1213.86
Subtracting 432 from 440 leaves us with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Advancing to step 8:
80 divided by 72 is 1 with a remainder of 8.
Put 1 as the next digit of the answer. 
Result so far: 1213.861
Subtracting 72 from 80 leaves us with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Going ahead to step 9:
When dividing 80 by 72, we get 1 with a remainder of 8.
Record the quotient 1 as the next digit in the result. 
Result so far: 1213.8611
Deduct 72 from 80 and we're left with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Our division results in 1213.8611 with a remaining 8e-05.