We look at the division of 55221 by 21 
We want to figure out the number of times 55221 can be divided by 21.

On to step 1:
When dividing 5 by 21, we get 0 with a remainder of 5.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 5 leaves us with 5.
Append the next digit (5) from the dividend to 5 and continue with: 55 / 21

Advancing to step 2:
55 divided by 21 is 2 with a remainder of 13.
Record the quotient 2 as the next digit in the result. 
Result so far: 2.0
If we take 42 away from 55, we end up with 13.
Grab the next digit (2) from the dividend, add it to 13, then carry on: 132 / 21

Going ahead to step 3:
21 goes into 132 6 times with a remainder of 6.
Write down 6 as next digit of the result. 
Result so far: 26.0
Deduct 126 from 132 and we're left with 6.
Fetch the next digit (2) from the dividend, attach it to 6 and continue: 62 / 21

Going ahead to step 4:
21 can be fit into 62 2 times, resulting in a remainder of 20.
Use 2 as the next digit of our solution. 
Result so far: 262.0
Deduct 42 from 62 and we're left with 20.
Include the next digit (1) from the dividend after 20, then repeat: 201 / 21

Step 5:
The number 21 fits into 201 9 times, leaving a remainder of 12.
The number 9 becomes the next digit in our result. 
Result so far: 2629.0
Subtract 189 from 201 to get 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Step 6:
21 can be fit into 120 5 times, resulting in a remainder of 15.
Write down 5 as next digit of the result. 
Result so far: 2629.5
Subtracting 105 from 120 leaves us with 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

On to step 7:
When dividing 150 by 21, we get 7 with a remainder of 3.
The next digit of our result is 7. 
Result so far: 2629.57
If we take 147 away from 150, we end up with 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Advancing to step 8:
If we divide 30 by 21, we get 1 and a remainder of 9.
Put 1 as the next digit of the answer. 
Result so far: 2629.571
If we subtract 21 from 30, we 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.

Moving on to step 9:
When dividing 90 by 21, we get 4 with a remainder of 6.
The next digit of our result is 4. 
Result so far: 2629.5714
Subtract 84 from 90 to 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.

Advancing to step 10:
When dividing 60 by 21, we get 2 with a remainder of 18.
Record the quotient 2 as the next digit in the result. 
Result so far: 2629.57142
The remainder is 18 after subtracting 42 from 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Going ahead to step 11:
When dividing 180 by 21, we get 8 with a remainder of 12.
The next digit of our result is 8. 
Result so far: 2629.571428
Subtracting 168 from 180 leaves us with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Step 12:
The number 21 fits into 120 5 times, leaving a remainder of 15.
Write down 5 as next digit of the result. 
Result so far: 2629.5714285
If we take 105 away from 120, we end up with 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

On to step 13:
150 divided by 21 is 7 with a remainder of 3.
The number 7 becomes the next digit in our result. 
Result so far: 2629.57142857
Deduct 147 from 150 and we're left with 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

The quotient of the division is 2629.57142857, and the remainder is 3e-09.