We look at the division of 345351 by 12 
Let's see how many times 12 fits into 345351.

Moving on to step 1:
12 goes into 3 0 times with a remainder of 3.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 3, we get 3.
Take the next digit (4) from the dividend and append it to 3, then repeat: 34 / 12

Moving on to step 2:
12 can be fit into 34 2 times, resulting in a remainder of 10.
Record the quotient 2 as the next digit in the result. 
Result so far: 2.0
Subtract 24 from 34 to get 10.
Fetch the next digit (5) from the dividend, attach it to 10 and continue: 105 / 12

Step 3:
12 goes into 105 8 times with a remainder of 9.
Write down 8 as next digit of the result. 
Result so far: 28.0
Subtracting 96 from 105 leaves us with 9.
Bring next digit (3) of the dividend behind the 9 and repeat the process: 93 / 12

Step 4:
When dividing 93 by 12, we get 7 with a remainder of 9.
The next digit of our result is 7. 
Result so far: 287.0
The remainder is 9 after subtracting 84 from 93.
Append the next digit (5) from the dividend to 9 and continue with: 95 / 12

Advancing to step 5:
95 divided by 12 is 7 with a remainder of 11.
The number 7 becomes the next digit in our result. 
Result so far: 2877.0
If we take 84 away from 95, we end up with 11.
Append the next digit (1) from the dividend to 11 and continue with: 111 / 12

On to step 6:
12 goes into 111 9 times with a remainder of 3.
The number 9 becomes the next digit in our result. 
Result so far: 28779.0
Subtracting 108 from 111 leaves us with 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Going ahead to step 7:
12 goes into 30 2 times with a remainder of 6.
The number 2 becomes the next digit in our result. 
Result so far: 28779.2
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.

Step 8:
12 goes into 60 5 times with a remainder of 0.
The next digit of our result is 5. 
Result so far: 28779.25
Deduct 60 from 60 and we're left 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.

Let's proceed to step 9:
12 goes into 0 0 times with a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 28779.25
If we subtract 0 from 0, we get 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:
12 can be fit into 0 0 times, resulting in a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 28779.25
Subtracting 0 from 0 leaves us 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.

The final result is 28779.25 with a remainder of 0.0.