We look at the division of 12129 by 61 
We want to divide 12129 by 61.

On to step 1:
61 goes into 1 0 times with a remainder of 1.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtracting 0 from 1 leaves us with 1.
Fetch the next digit (2) from the dividend, attach it to 1 and continue: 12 / 61

Moving on to step 2:
12 divided by 61 is 0 with a remainder of 12.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 12 after subtracting 0 from 12.
Include the next digit (1) from the dividend after 12, then repeat: 121 / 61

On to step 3:
When dividing 121 by 61, we get 1 with a remainder of 60.
Write down 1 as next digit of the result. 
Result so far: 1.0
If we subtract 61 from 121, we get 60.
Bring next digit (2) of the dividend behind the 60 and repeat the process: 602 / 61

Step 4:
When dividing 602 by 61, we get 9 with a remainder of 53.
Record the quotient 9 as the next digit in the result. 
Result so far: 19.0
If we take 549 away from 602, we end up with 53.
Grab the next digit (9) from the dividend, add it to 53, then carry on: 539 / 61

Let's proceed to step 5:
When dividing 539 by 61, we get 8 with a remainder of 51.
Use 8 as the next digit of our solution. 
Result so far: 198.0
If we subtract 488 from 539, we get 51.
Since there are no more digits in the dividend, we add a zero to the remainder making it 510, and continue the process.

Moving on to step 6:
If we divide 510 by 61, we get 8 and a remainder of 22.
The number 8 becomes the next digit in our result. 
Result so far: 198.8
Subtract 488 from 510 to get 22.
Since there are no more digits in the dividend, we add a zero to the remainder making it 220, and continue the process.

On to step 7:
When dividing 220 by 61, we get 3 with a remainder of 37.
Put 3 as the next digit of the answer. 
Result so far: 198.83
Deduct 183 from 220 and we're left with 37.
Since there are no more digits in the dividend, we add a zero to the remainder making it 370, and continue the process.

Moving on to step 8:
When dividing 370 by 61, we get 6 with a remainder of 4.
Put 6 as the next digit of the answer. 
Result so far: 198.836
If we subtract 366 from 370, we 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.

Advancing to step 9:
40 divided by 61 is 0 with a remainder of 40.
The next digit of our result is 0. 
Result so far: 198.836
The remainder is 40 after subtracting 0 from 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Let's proceed to step 10:
When dividing 400 by 61, we get 6 with a remainder of 34.
Put 6 as the next digit of the answer. 
Result so far: 198.83606
Subtract 366 from 400 to get 34.
Since there are no more digits in the dividend, we add a zero to the remainder making it 340, and continue the process.

Step 11:
When dividing 340 by 61, we get 5 with a remainder of 35.
Write down 5 as next digit of the result. 
Result so far: 198.836065
Deduct 305 from 340 and we're left with 35.
Since there are no more digits in the dividend, we add a zero to the remainder making it 350, and continue the process.

Advancing to step 12:
If we divide 350 by 61, we get 5 and a remainder of 45.
Put 5 as the next digit of the answer. 
Result so far: 198.8360655
Deduct 305 from 350 and we're left with 45.
Since there are no more digits in the dividend, we add a zero to the remainder making it 450, and continue the process.

The final result is 198.8360655 with a remainder of 4.5e-07.