12390975 divided by 172 
Our goal is to divide 12390975 by 172.

Step 1:
The number 172 fits into 1 0 times, leaving a remainder of 1.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 1 to get 1.
Append the next digit (2) from the dividend to 1 and continue with: 12 / 172

Going ahead to step 2:
12 divided by 172 is 0 with a remainder of 12.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 12 and we're left with 12.
Grab the next digit (3) from the dividend, add it to 12, then carry on: 123 / 172

Going ahead to step 3:
When dividing 123 by 172, we get 0 with a remainder of 123.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we take 0 away from 123, we end up with 123.
Fetch the next digit (9) from the dividend, attach it to 123 and continue: 1239 / 172

Going ahead to step 4:
The number 172 fits into 1239 7 times, leaving a remainder of 35.
Put 7 as the next digit of the answer. 
Result so far: 7.0
Subtract 1204 from 1239 to get 35.
Bring next digit (0) of the dividend behind the 35 and repeat the process: 350 / 172

Going ahead to step 5:
172 can be fit into 350 2 times, resulting in a remainder of 6.
Record the quotient 2 as the next digit in the result. 
Result so far: 72.0
The remainder is 6 after subtracting 344 from 350.
Take the next digit (9) from the dividend and append it to 6, then repeat: 69 / 172

Moving on to step 6:
When dividing 69 by 172, we get 0 with a remainder of 69.
Write down 0 as next digit of the result. 
Result so far: 720.0
If we take 0 away from 69, we end up with 69.
Bring next digit (7) of the dividend behind the 69 and repeat the process: 697 / 172

Moving on to step 7:
172 can be fit into 697 4 times, resulting in a remainder of 9.
Record the quotient 4 as the next digit in the result. 
Result so far: 7204.0
Subtract 688 from 697 to get 9.
Bring next digit (5) of the dividend behind the 9 and repeat the process: 95 / 172

Moving on to step 8:
172 can be fit into 95 0 times, resulting in a remainder of 95.
The next digit of our result is 0. 
Result so far: 72040.0
The remainder is 95 after subtracting 0 from 95.
Since there are no more digits in the dividend, we add a zero to the remainder making it 950, and continue the process.

Let's proceed to step 9:
950 divided by 172 is 5 with a remainder of 90.
The number 5 becomes the next digit in our result. 
Result so far: 72040.5
Subtracting 860 from 950 leaves us with 90.
Since there are no more digits in the dividend, we add a zero to the remainder making it 900, and continue the process.

Advancing to step 10:
When dividing 900 by 172, we get 5 with a remainder of 40.
Record the quotient 5 as the next digit in the result. 
Result so far: 72040.55
If we subtract 860 from 900, 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.

In conclusion, the division gives 72040.55 with a balance of 0.04.