We divide 256866 by 12
We're looking to find how many times 12 goes into 256866.

Let's proceed to step 1:
12 can be fit into 2 0 times, resulting in a remainder of 2.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we take 0 away from 2, we end up with 2.
Fetch the next digit (5) from the dividend, attach it to 2 and continue: 25 / 12

Advancing to step 2:
When dividing 25 by 12, we get 2 with a remainder of 1.
Write down 2 as next digit of the result. 
Result so far: 2.0
Deduct 24 from 25 and we're left with 1.
Take the next digit (6) from the dividend and append it to 1, then repeat: 16 / 12

Moving on to step 3:
12 can be fit into 16 1 times, resulting in a remainder of 4.
Write down 1 as next digit of the result. 
Result so far: 21.0
Deduct 12 from 16 and we're left with 4.
Take the next digit (8) from the dividend and append it to 4, then repeat: 48 / 12

Let's proceed to step 4:
48 divided by 12 is 4 with a remainder of 0.
Record the quotient 4 as the next digit in the result. 
Result so far: 214.0
Subtracting 48 from 48 leaves us with 0.
Append the next digit (6) from the dividend to 0 and continue with: 6 / 12

Let's proceed to step 5:
12 can be fit into 6 0 times, resulting in a remainder of 6.
Put 0 as the next digit of the answer. 
Result so far: 2140.0
The remainder is 6 after subtracting 0 from 6.
Include the next digit (6) from the dividend after 6, then repeat: 66 / 12

Going ahead to step 6:
12 can be fit into 66 5 times, resulting in a remainder of 6.
Record the quotient 5 as the next digit in the result. 
Result so far: 21405.0
Subtract 60 from 66 to get 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Advancing to step 7:
60 divided by 12 is 5 with a remainder of 0.
Record the quotient 5 as the next digit in the result. 
Result so far: 21405.5
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.

Moving on to step 8:
12 goes into 0 0 times with a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 21405.5
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.

Step 9:
The number 12 fits into 0 0 times, leaving a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 21405.5
Deduct 0 from 0 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.

The final outcome is 21405.5, with a leftover of 0.0.