We look at the division of 445743 by 21 
We want to figure out the number of times 445743 can be divided by 21.

On to step 1:
21 goes into 4 0 times with a remainder of 4.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 4 leaves us with 4.
Fetch the next digit (4) from the dividend, attach it to 4 and continue: 44 / 21

Going ahead to step 2:
The number 21 fits into 44 2 times, leaving a remainder of 2.
The number 2 becomes the next digit in our result. 
Result so far: 2.0
The remainder is 2 after subtracting 42 from 44.
Take the next digit (5) from the dividend and append it to 2, then repeat: 25 / 21

On to step 3:
When dividing 25 by 21, we get 1 with a remainder of 4.
Put 1 as the next digit of the answer. 
Result so far: 21.0
Subtracting 21 from 25 leaves us with 4.
Fetch the next digit (7) from the dividend, attach it to 4 and continue: 47 / 21

Moving on to step 4:
21 can be fit into 47 2 times, resulting in a remainder of 5.
Put 2 as the next digit of the answer. 
Result so far: 212.0
Subtract 42 from 47 to get 5.
Bring next digit (4) of the dividend behind the 5 and repeat the process: 54 / 21

Going ahead to step 5:
If we divide 54 by 21, we get 2 and a remainder of 12.
The number 2 becomes the next digit in our result. 
Result so far: 2122.0
Deduct 42 from 54 and we're left with 12.
Append the next digit (3) from the dividend to 12 and continue with: 123 / 21

Let's proceed to step 6:
The number 21 fits into 123 5 times, leaving a remainder of 18.
Put 5 as the next digit of the answer. 
Result so far: 21225.0
The remainder is 18 after subtracting 105 from 123.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

On to step 7:
21 goes into 180 8 times with a remainder of 12.
Put 8 as the next digit of the answer. 
Result so far: 21225.8
The remainder is 12 after subtracting 168 from 180.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Moving on to step 8:
The number 21 fits into 120 5 times, leaving a remainder of 15.
The number 5 becomes the next digit in our result. 
Result so far: 21225.85
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.

Step 9:
When dividing 150 by 21, we get 7 with a remainder of 3.
Write down 7 as next digit of the result. 
Result so far: 21225.857
Subtract 147 from 150 to get 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Moving on to step 10:
21 goes into 30 1 times with a remainder of 9.
The number 1 becomes the next digit in our result. 
Result so far: 21225.8571
Deduct 21 from 30 and we're left with 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 11:
If we divide 90 by 21, we get 4 and a remainder of 6.
Put 4 as the next digit of the answer. 
Result so far: 21225.85714
The remainder is 6 after subtracting 84 from 90.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Let's proceed to step 12:
When dividing 60 by 21, we get 2 with a remainder of 18.
The next digit of our result is 2. 
Result so far: 21225.857142
Deduct 42 from 60 and we're left with 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Moving on to step 13:
180 divided by 21 is 8 with a remainder of 12.
Record the quotient 8 as the next digit in the result. 
Result so far: 21225.8571428
Deduct 168 from 180 and we're left 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 14:
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: 21225.85714285
If we subtract 105 from 120, we get 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

After the division, we end up with 21225.85714285 and a remainder of 1.5e-08.