We're dividing 20121 by 77 
We're looking to find how many times 77 goes into 20121.

Advancing to step 1:
The number 77 fits into 2 0 times, leaving a remainder of 2.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 2, we end up with 2.
Grab the next digit (0) from the dividend, add it to 2, then carry on: 20 / 77

Going ahead to step 2:
77 goes into 20 0 times with a remainder of 20.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
The remainder is 20 after subtracting 0 from 20.
Append the next digit (1) from the dividend to 20 and continue with: 201 / 77

Advancing to step 3:
77 goes into 201 2 times with a remainder of 47.
Record the quotient 2 as the next digit in the result. 
Result so far: 2.0
If we subtract 154 from 201, we get 47.
Take the next digit (2) from the dividend and append it to 47, then repeat: 472 / 77

Let's proceed to step 4:
When dividing 472 by 77, we get 6 with a remainder of 10.
Write down 6 as next digit of the result. 
Result so far: 26.0
If we take 462 away from 472, we end up with 10.
Fetch the next digit (1) from the dividend, attach it to 10 and continue: 101 / 77

Going ahead to step 5:
77 goes into 101 1 times with a remainder of 24.
The next digit of our result is 1. 
Result so far: 261.0
Deduct 77 from 101 and we're left with 24.
Since there are no more digits in the dividend, we add a zero to the remainder making it 240, and continue the process.

Going ahead to step 6:
240 divided by 77 is 3 with a remainder of 9.
The number 3 becomes the next digit in our result. 
Result so far: 261.3
Subtract 231 from 240 to get 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Let's proceed to step 7:
If we divide 90 by 77, we get 1 and a remainder of 13.
Write down 1 as next digit of the result. 
Result so far: 261.31
Subtract 77 from 90 to get 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Advancing to step 8:
The number 77 fits into 130 1 times, leaving a remainder of 53.
Write down 1 as next digit of the result. 
Result so far: 261.311
If we subtract 77 from 130, we get 53.
Since there are no more digits in the dividend, we add a zero to the remainder making it 530, and continue the process.

The final result is 261.311 with a remainder of 0.0053.