We divide 321399 by 12
Let's see how many times 12 fits into 321399.

Step 1:
3 divided by 12 is 0 with a remainder of 3.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
The remainder is 3 after subtracting 0 from 3.
Bring next digit (2) of the dividend behind the 3 and repeat the process: 32 / 12

Advancing to step 2:
32 divided by 12 is 2 with a remainder of 8.
The next digit of our result is 2. 
Result so far: 2.0
Subtracting 24 from 32 leaves us with 8.
Include the next digit (1) from the dividend after 8, then repeat: 81 / 12

On to step 3:
12 goes into 81 6 times with a remainder of 9.
Use 6 as the next digit of our solution. 
Result so far: 26.0
If we take 72 away from 81, we end up with 9.
Include the next digit (3) from the dividend after 9, then repeat: 93 / 12

On to step 4:
93 divided by 12 is 7 with a remainder of 9.
Record the quotient 7 as the next digit in the result. 
Result so far: 267.0
Subtract 84 from 93 to get 9.
Take the next digit (9) from the dividend and append it to 9, then repeat: 99 / 12

Advancing to step 5:
The number 12 fits into 99 8 times, leaving a remainder of 3.
Put 8 as the next digit of the answer. 
Result so far: 2678.0
The remainder is 3 after subtracting 96 from 99.
Fetch the next digit (9) from the dividend, attach it to 3 and continue: 39 / 12

Let's proceed to step 6:
12 can be fit into 39 3 times, resulting in a remainder of 3.
The number 3 becomes the next digit in our result. 
Result so far: 26783.0
Subtract 36 from 39 to get 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

On to step 7:
30 divided by 12 is 2 with a remainder of 6.
The number 2 becomes the next digit in our result. 
Result so far: 26783.2
Subtracting 24 from 30 leaves us with 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Moving on to step 8:
12 can be fit into 60 5 times, resulting in a remainder of 0.
Write down 5 as next digit of the result. 
Result so far: 26783.25
If we take 60 away from 60, we end up with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Going ahead to step 9:
If we divide 0 by 12, we get 0 and a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 26783.25
If we take 0 away from 0, we end up with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

On to step 10:
When dividing 0 by 12, we get 0 with a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 26783.25
The remainder is 0 after subtracting 0 from 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Our division results in 26783.25 with a remaining 0.0.