We're dividing 21015 by 77 
We want to divide 21015 by 77.

Advancing to step 1:
77 goes into 2 0 times with a remainder of 2.
The next digit of our result is 0. 
Result so far: 0.0
If we take 0 away from 2, we end up with 2.
Append the next digit (1) from the dividend to 2 and continue with: 21 / 77

Advancing to step 2:
77 goes into 21 0 times with a remainder of 21.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtracting 0 from 21 leaves us with 21.
Append the next digit (0) from the dividend to 21 and continue with: 210 / 77

Advancing to step 3:
210 divided by 77 is 2 with a remainder of 56.
The next digit of our result is 2. 
Result so far: 2.0
Subtract 154 from 210 to get 56.
Grab the next digit (1) from the dividend, add it to 56, then carry on: 561 / 77

On to step 4:
561 divided by 77 is 7 with a remainder of 22.
Write down 7 as next digit of the result. 
Result so far: 27.0
If we subtract 539 from 561, we get 22.
Fetch the next digit (5) from the dividend, attach it to 22 and continue: 225 / 77

Step 5:
If we divide 225 by 77, we get 2 and a remainder of 71.
Put 2 as the next digit of the answer. 
Result so far: 272.0
The remainder is 71 after subtracting 154 from 225.
Since there are no more digits in the dividend, we add a zero to the remainder making it 710, and continue the process.

Going ahead to step 6:
77 goes into 710 9 times with a remainder of 17.
Record the quotient 9 as the next digit in the result. 
Result so far: 272.9
Subtracting 693 from 710 leaves us with 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Moving on to step 7:
77 goes into 170 2 times with a remainder of 16.
The next digit of our result is 2. 
Result so far: 272.92
Subtracting 154 from 170 leaves us with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Moving on to step 8:
160 divided by 77 is 2 with a remainder of 6.
Put 2 as the next digit of the answer. 
Result so far: 272.922
If we subtract 154 from 160, we 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.

The final outcome is 272.922, with a leftover of 0.0006.