We look at the division of 42172109 by 831 
Let's see how many times 831 fits into 42172109.

Advancing to step 1:
831 can be fit into 4 0 times, resulting in a remainder of 4.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 4 to get 4.
Bring next digit (2) of the dividend behind the 4 and repeat the process: 42 / 831

On to step 2:
The number 831 fits into 42 0 times, leaving a remainder of 42.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we take 0 away from 42, we end up with 42.
Grab the next digit (1) from the dividend, add it to 42, then carry on: 421 / 831

On to step 3:
When dividing 421 by 831, we get 0 with a remainder of 421.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 421, we get 421.
Grab the next digit (7) from the dividend, add it to 421, then carry on: 4217 / 831

Let's proceed to step 4:
If we divide 4217 by 831, we get 5 and a remainder of 62.
Put 5 as the next digit of the answer. 
Result so far: 5.0
Deduct 4155 from 4217 and we're left with 62.
Fetch the next digit (2) from the dividend, attach it to 62 and continue: 622 / 831

Moving on to step 5:
831 can be fit into 622 0 times, resulting in a remainder of 622.
The number 0 becomes the next digit in our result. 
Result so far: 50.0
Subtract 0 from 622 to get 622.
Fetch the next digit (1) from the dividend, attach it to 622 and continue: 6221 / 831

On to step 6:
831 goes into 6221 7 times with a remainder of 404.
The next digit of our result is 7. 
Result so far: 507.0
If we subtract 5817 from 6221, we get 404.
Bring next digit (0) of the dividend behind the 404 and repeat the process: 4040 / 831

Step 7:
If we divide 4040 by 831, we get 4 and a remainder of 716.
Put 4 as the next digit of the answer. 
Result so far: 5074.0
Subtract 3324 from 4040 to get 716.
Bring next digit (9) of the dividend behind the 716 and repeat the process: 7169 / 831

Going ahead to step 8:
When dividing 7169 by 831, we get 8 with a remainder of 521.
Use 8 as the next digit of our solution. 
Result so far: 50748.0
Subtracting 6648 from 7169 leaves us with 521.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5210, and continue the process.

On to step 9:
831 goes into 5210 6 times with a remainder of 224.
Write down 6 as next digit of the result. 
Result so far: 50748.6
Subtract 4986 from 5210 to get 224.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2240, and continue the process.

Step 10:
2240 divided by 831 is 2 with a remainder of 578.
Record the quotient 2 as the next digit in the result. 
Result so far: 50748.62
Deduct 1662 from 2240 and we're left with 578.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5780, and continue the process.

Moving on to step 11:
When dividing 5780 by 831, we get 6 with a remainder of 794.
Put 6 as the next digit of the answer. 
Result so far: 50748.626
Deduct 4986 from 5780 and we're left with 794.
Since there are no more digits in the dividend, we add a zero to the remainder making it 7940, and continue the process.

Let's proceed to step 12:
7940 divided by 831 is 9 with a remainder of 461.
Put 9 as the next digit of the answer. 
Result so far: 50748.6269
Subtracting 7479 from 7940 leaves us with 461.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4610, and continue the process.

Step 13:
If we divide 4610 by 831, we get 5 and a remainder of 455.
Record the quotient 5 as the next digit in the result. 
Result so far: 50748.62695
Subtract 4155 from 4610 to get 455.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4550, and continue the process.

Step 14:
When dividing 4550 by 831, we get 5 with a remainder of 395.
Write down 5 as next digit of the result. 
Result so far: 50748.626955
If we take 4155 away from 4550, we end up with 395.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3950, and continue the process.

The quotient of the division is 50748.626955, and the remainder is 3.95e-05.