We're dividing 443877 by 21 
We want to figure out the number of times 443877 can be divided by 21.

Going ahead to step 1:
If we divide 4 by 21, we get 0 and a remainder of 4.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 4, we get 4.
Bring next digit (4) of the dividend behind the 4 and repeat the process: 44 / 21

On to step 2:
44 divided by 21 is 2 with a remainder of 2.
The number 2 becomes the next digit in our result. 
Result so far: 2.0
Deduct 42 from 44 and we're left with 2.
Fetch the next digit (3) from the dividend, attach it to 2 and continue: 23 / 21

Step 3:
21 can be fit into 23 1 times, resulting in a remainder of 2.
Record the quotient 1 as the next digit in the result. 
Result so far: 21.0
The remainder is 2 after subtracting 21 from 23.
Take the next digit (8) from the dividend and append it to 2, then repeat: 28 / 21

Moving on to step 4:
When dividing 28 by 21, we get 1 with a remainder of 7.
The number 1 becomes the next digit in our result. 
Result so far: 211.0
Deduct 21 from 28 and we're left with 7.
Fetch the next digit (7) from the dividend, attach it to 7 and continue: 77 / 21

Moving on to step 5:
21 goes into 77 3 times with a remainder of 14.
Write down 3 as next digit of the result. 
Result so far: 2113.0
If we take 63 away from 77, we end up with 14.
Bring next digit (7) of the dividend behind the 14 and repeat the process: 147 / 21

Let's proceed to step 6:
147 divided by 21 is 7 with a remainder of 0.
Use 7 as the next digit of our solution. 
Result so far: 21137.0
Subtracting 147 from 147 leaves us with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Let's proceed to step 7:
When dividing 0 by 21, we get 0 with a remainder of 0.
Record the quotient 0 as the next digit in the result. 
Result so far: 21137.0
Subtract 0 from 0 to get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Advancing to step 8:
21 can be fit into 0 0 times, resulting in a remainder of 0.
The next digit of our result is 0. 
Result so far: 21137.0
Subtracting 0 from 0 leaves us with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

After the division, we end up with 21137.0 and a remainder of 0.0.