121541 divided by 21 
Let's see how many times 21 fits into 121541.

On to step 1:
21 goes into 1 0 times with 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.
Take the next digit (2) from the dividend and append it to 1, then repeat: 12 / 21

On to step 2:
If we divide 12 by 21, we get 0 and a remainder of 12.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we take 0 away from 12, we end up with 12.
Include the next digit (1) from the dividend after 12, then repeat: 121 / 21

Moving on to step 3:
121 divided by 21 is 5 with a remainder of 16.
The number 5 becomes the next digit in our result. 
Result so far: 5.0
If we subtract 105 from 121, we get 16.
Include the next digit (5) from the dividend after 16, then repeat: 165 / 21

Going ahead to step 4:
The number 21 fits into 165 7 times, leaving a remainder of 18.
The next digit of our result is 7. 
Result so far: 57.0
Deduct 147 from 165 and we're left with 18.
Include the next digit (4) from the dividend after 18, then repeat: 184 / 21

Going ahead to step 5:
21 goes into 184 8 times with a remainder of 16.
The next digit of our result is 8. 
Result so far: 578.0
Deduct 168 from 184 and we're left with 16.
Fetch the next digit (1) from the dividend, attach it to 16 and continue: 161 / 21

On to step 6:
The number 21 fits into 161 7 times, leaving a remainder of 14.
Record the quotient 7 as the next digit in the result. 
Result so far: 5787.0
Subtracting 147 from 161 leaves us with 14.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

Advancing to step 7:
The number 21 fits into 140 6 times, leaving a remainder of 14.
Write down 6 as next digit of the result. 
Result so far: 5787.6
Subtracting 126 from 140 leaves us with 14.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

Advancing to step 8:
21 can be fit into 140 6 times, resulting in a remainder of 14.
Write down 6 as next digit of the result. 
Result so far: 5787.66
If we take 126 away from 140, we end up with 14.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

After the division, we end up with 5787.66 and a remainder of 0.014.