138121 divided by 12 
We want to divide 138121 by 12.

Advancing to step 1:
The number 12 fits into 1 0 times, leaving a remainder of 1.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 1 to get 1.
Bring next digit (3) of the dividend behind the 1 and repeat the process: 13 / 12

Let's proceed to step 2:
12 can be fit into 13 1 times, resulting in a remainder of 1.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
If we take 12 away from 13, we end up with 1.
Take the next digit (8) from the dividend and append it to 1, then repeat: 18 / 12

Step 3:
12 can be fit into 18 1 times, resulting in a remainder of 6.
Use 1 as the next digit of our solution. 
Result so far: 11.0
Subtracting 12 from 18 leaves us with 6.
Grab the next digit (1) from the dividend, add it to 6, then carry on: 61 / 12

Going ahead to step 4:
12 can be fit into 61 5 times, resulting in a remainder of 1.
Put 5 as the next digit of the answer. 
Result so far: 115.0
If we subtract 60 from 61, we get 1.
Take the next digit (2) from the dividend and append it to 1, then repeat: 12 / 12

Let's proceed to step 5:
12 goes into 12 1 times with a remainder of 0.
Use 1 as the next digit of our solution. 
Result so far: 1151.0
If we subtract 12 from 12, we get 0.
Append the next digit (1) from the dividend to 0 and continue with: 1 / 12

On to step 6:
If we divide 1 by 12, we get 0 and a remainder of 1.
The number 0 becomes the next digit in our result. 
Result so far: 11510.0
Deduct 0 from 1 and we're left with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Let's proceed to step 7:
10 divided by 12 is 0 with a remainder of 10.
The number 0 becomes the next digit in our result. 
Result so far: 11510.0
If we take 0 away from 10, we end up with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Moving on to step 8:
If we divide 100 by 12, we get 8 and a remainder of 4.
The next digit of our result is 8. 
Result so far: 11510.08
Subtracting 96 from 100 leaves us with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

On to step 9:
When dividing 40 by 12, we get 3 with a remainder of 4.
Record the quotient 3 as the next digit in the result. 
Result so far: 11510.083
The remainder is 4 after subtracting 36 from 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Step 10:
12 goes into 40 3 times with a remainder of 4.
Use 3 as the next digit of our solution. 
Result so far: 11510.0833
Subtract 36 from 40 to get 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Our division results in 11510.0833 with a remaining 4e-05.