170105 ÷ 12 
We're looking to find how many times 12 goes into 170105.

Let's proceed to step 1:
12 can be fit into 1 0 times, resulting in a remainder of 1.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 1 and we're left with 1.
Include the next digit (7) from the dividend after 1, then repeat: 17 / 12

On to step 2:
When dividing 17 by 12, we get 1 with a remainder of 5.
The next digit of our result is 1. 
Result so far: 1.0
Subtracting 12 from 17 leaves us with 5.
Take the next digit (0) from the dividend and append it to 5, then repeat: 50 / 12

On to step 3:
The number 12 fits into 50 4 times, leaving a remainder of 2.
Write down 4 as next digit of the result. 
Result so far: 14.0
If we take 48 away from 50, we end up with 2.
Include the next digit (1) from the dividend after 2, then repeat: 21 / 12

On to step 4:
12 can be fit into 21 1 times, resulting in a remainder of 9.
Write down 1 as next digit of the result. 
Result so far: 141.0
Subtracting 12 from 21 leaves us with 9.
Bring next digit (0) of the dividend behind the 9 and repeat the process: 90 / 12

Advancing to step 5:
12 can be fit into 90 7 times, resulting in a remainder of 6.
The number 7 becomes the next digit in our result. 
Result so far: 1417.0
Subtract 84 from 90 to get 6.
Grab the next digit (5) from the dividend, add it to 6, then carry on: 65 / 12

On to step 6:
65 divided by 12 is 5 with a remainder of 5.
Put 5 as the next digit of the answer. 
Result so far: 14175.0
If we take 60 away from 65, we end up with 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

On to step 7:
12 goes into 50 4 times with a remainder of 2.
Use 4 as the next digit of our solution. 
Result so far: 14175.4
If we take 48 away from 50, we end up with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Step 8:
12 goes into 20 1 times with a remainder of 8.
Use 1 as the next digit of our solution. 
Result so far: 14175.41
Subtract 12 from 20 to get 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

On to step 9:
80 divided by 12 is 6 with a remainder of 8.
Put 6 as the next digit of the answer. 
Result so far: 14175.416
If we subtract 72 from 80, we get 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 10:
When dividing 80 by 12, we get 6 with a remainder of 8.
Record the quotient 6 as the next digit in the result. 
Result so far: 14175.4166
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.

The final result is 14175.4166 with a remainder of 8e-05.