We look at the division of 26139 by 12 
We want to divide 26139 by 12.

Step 1:
When dividing 2 by 12, we get 0 with a remainder of 2.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 2, we get 2.
Take the next digit (6) from the dividend and append it to 2, then repeat: 26 / 12

Advancing to step 2:
26 divided by 12 is 2 with a remainder of 2.
The number 2 becomes the next digit in our result. 
Result so far: 2.0
If we subtract 24 from 26, we get 2.
Bring next digit (1) of the dividend behind the 2 and repeat the process: 21 / 12

On to step 3:
21 divided by 12 is 1 with a remainder of 9.
Record the quotient 1 as the next digit in the result. 
Result so far: 21.0
If we take 12 away from 21, we end up with 9.
Grab the next digit (3) from the dividend, add it to 9, then carry on: 93 / 12

Moving on to step 4:
12 can be fit into 93 7 times, resulting in a remainder of 9.
The number 7 becomes the next digit in our result. 
Result so far: 217.0
If we take 84 away from 93, we end up with 9.
Include the next digit (9) from the dividend after 9, then repeat: 99 / 12

Let's proceed to step 5:
When dividing 99 by 12, we get 8 with a remainder of 3.
The next digit of our result is 8. 
Result so far: 2178.0
Subtracting 96 from 99 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.

Advancing to step 6:
If we divide 30 by 12, we get 2 and a remainder of 6.
Write down 2 as next digit of the result. 
Result so far: 2178.2
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.

On to step 7:
When dividing 60 by 12, we get 5 with a remainder of 0.
The next digit of our result is 5. 
Result so far: 2178.25
Subtracting 60 from 60 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.

On to step 8:
0 divided by 12 is 0 with a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 2178.25
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.

Advancing to step 9:
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: 2178.25
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.

The final result is 2178.25 with a remainder of 0.0.