We look at the division of 12258842 by 172 
We're looking to find how many times 172 goes into 12258842.

Going ahead to step 1:
1 divided by 172 is 0 with a remainder of 1.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we subtract 0 from 1, we get 1.
Fetch the next digit (2) from the dividend, attach it to 1 and continue: 12 / 172

Moving on to step 2:
172 goes into 12 0 times with a remainder of 12.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 12, we get 12.
Include the next digit (2) from the dividend after 12, then repeat: 122 / 172

On to step 3:
122 divided by 172 is 0 with a remainder of 122.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtracting 0 from 122 leaves us with 122.
Grab the next digit (5) from the dividend, add it to 122, then carry on: 1225 / 172

Advancing to step 4:
1225 divided by 172 is 7 with a remainder of 21.
The next digit of our result is 7. 
Result so far: 7.0
Deduct 1204 from 1225 and we're left with 21.
Fetch the next digit (8) from the dividend, attach it to 21 and continue: 218 / 172

Moving on to step 5:
218 divided by 172 is 1 with a remainder of 46.
Put 1 as the next digit of the answer. 
Result so far: 71.0
Subtract 172 from 218 to get 46.
Bring next digit (8) of the dividend behind the 46 and repeat the process: 468 / 172

Moving on to step 6:
If we divide 468 by 172, we get 2 and a remainder of 124.
Use 2 as the next digit of our solution. 
Result so far: 712.0
If we subtract 344 from 468, we get 124.
Include the next digit (4) from the dividend after 124, then repeat: 1244 / 172

On to step 7:
The number 172 fits into 1244 7 times, leaving a remainder of 40.
Write down 7 as next digit of the result. 
Result so far: 7127.0
Subtract 1204 from 1244 to get 40.
Include the next digit (2) from the dividend after 40, then repeat: 402 / 172

Let's proceed to step 8:
172 can be fit into 402 2 times, resulting in a remainder of 58.
Write down 2 as next digit of the result. 
Result so far: 71272.0
The remainder is 58 after subtracting 344 from 402.
Since there are no more digits in the dividend, we add a zero to the remainder making it 580, and continue the process.

Moving on to step 9:
580 divided by 172 is 3 with a remainder of 64.
The number 3 becomes the next digit in our result. 
Result so far: 71272.3
Subtracting 516 from 580 leaves us with 64.
Since there are no more digits in the dividend, we add a zero to the remainder making it 640, and continue the process.

Step 10:
640 divided by 172 is 3 with a remainder of 124.
Use 3 as the next digit of our solution. 
Result so far: 71272.33
Subtracting 516 from 640 leaves us with 124.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1240, and continue the process.

After the division, we end up with 71272.33 and a remainder of 0.124.