We look at the division of 72172849 by 639 
The aim is to understand the frequency of 639 in 72172849.

Going ahead to step 1:
If we divide 7 by 639, we get 0 and a remainder of 7.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 7 to get 7.
Append the next digit (2) from the dividend to 7 and continue with: 72 / 639

Step 2:
639 can be fit into 72 0 times, resulting in a remainder of 72.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtract 0 from 72 to get 72.
Take the next digit (1) from the dividend and append it to 72, then repeat: 721 / 639

Let's proceed to step 3:
When dividing 721 by 639, we get 1 with a remainder of 82.
Use 1 as the next digit of our solution. 
Result so far: 1.0
If we subtract 639 from 721, we get 82.
Grab the next digit (7) from the dividend, add it to 82, then carry on: 827 / 639

On to step 4:
639 can be fit into 827 1 times, resulting in a remainder of 188.
Put 1 as the next digit of the answer. 
Result so far: 11.0
Subtract 639 from 827 to get 188.
Append the next digit (2) from the dividend to 188 and continue with: 1882 / 639

Moving on to step 5:
The number 639 fits into 1882 2 times, leaving a remainder of 604.
Put 2 as the next digit of the answer. 
Result so far: 112.0
Subtract 1278 from 1882 to get 604.
Append the next digit (8) from the dividend to 604 and continue with: 6048 / 639

Let's proceed to step 6:
If we divide 6048 by 639, we get 9 and a remainder of 297.
Write down 9 as next digit of the result. 
Result so far: 1129.0
Deduct 5751 from 6048 and we're left with 297.
Grab the next digit (4) from the dividend, add it to 297, then carry on: 2974 / 639

On to step 7:
639 goes into 2974 4 times with a remainder of 418.
Write down 4 as next digit of the result. 
Result so far: 11294.0
Subtracting 2556 from 2974 leaves us with 418.
Append the next digit (9) from the dividend to 418 and continue with: 4189 / 639

Moving on to step 8:
If we divide 4189 by 639, we get 6 and a remainder of 355.
Record the quotient 6 as the next digit in the result. 
Result so far: 112946.0
The remainder is 355 after subtracting 3834 from 4189.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3550, and continue the process.

Advancing to step 9:
639 can be fit into 3550 5 times, resulting in a remainder of 355.
Put 5 as the next digit of the answer. 
Result so far: 112946.5
Deduct 3195 from 3550 and we're left with 355.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3550, and continue the process.

On to step 10:
The number 639 fits into 3550 5 times, leaving a remainder of 355.
Put 5 as the next digit of the answer. 
Result so far: 112946.55
If we subtract 3195 from 3550, we get 355.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3550, and continue the process.

The quotient of the division is 112946.55, and the remainder is 0.355.