538353 divided by 21 
Let's see how many times 21 fits into 538353.

Moving on to step 1:
The number 21 fits into 5 0 times, leaving a remainder of 5.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtracting 0 from 5 leaves us with 5.
Append the next digit (3) from the dividend to 5 and continue with: 53 / 21

Step 2:
21 can be fit into 53 2 times, resulting in a remainder of 11.
Write down 2 as next digit of the result. 
Result so far: 2.0
Subtracting 42 from 53 leaves us with 11.
Take the next digit (8) from the dividend and append it to 11, then repeat: 118 / 21

On to step 3:
21 can be fit into 118 5 times, resulting in a remainder of 13.
Write down 5 as next digit of the result. 
Result so far: 25.0
Subtract 105 from 118 to get 13.
Fetch the next digit (3) from the dividend, attach it to 13 and continue: 133 / 21

On to step 4:
If we divide 133 by 21, we get 6 and a remainder of 7.
The next digit of our result is 6. 
Result so far: 256.0
If we take 126 away from 133, we end up with 7.
Take the next digit (5) from the dividend and append it to 7, then repeat: 75 / 21

On to step 5:
When dividing 75 by 21, we get 3 with a remainder of 12.
Put 3 as the next digit of the answer. 
Result so far: 2563.0
If we take 63 away from 75, we end up with 12.
Append the next digit (3) from the dividend to 12 and continue with: 123 / 21

Moving on to step 6:
When dividing 123 by 21, we get 5 with a remainder of 18.
The next digit of our result is 5. 
Result so far: 25635.0
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.

Advancing to step 7:
When dividing 180 by 21, we get 8 with a remainder of 12.
Write down 8 as next digit of the result. 
Result so far: 25635.8
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.

Let's proceed to step 8:
If we divide 120 by 21, we get 5 and a remainder of 15.
The next digit of our result is 5. 
Result so far: 25635.85
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.

Going ahead to step 9:
21 can be fit into 150 7 times, resulting in a remainder of 3.
The number 7 becomes the next digit in our result. 
Result so far: 25635.857
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.

Going ahead to step 10:
21 can be fit into 30 1 times, resulting in a remainder of 9.
Record the quotient 1 as the next digit in the result. 
Result so far: 25635.8571
The remainder is 9 after subtracting 21 from 30.
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:
The number 21 fits into 90 4 times, leaving a remainder of 6.
Write down 4 as next digit of the result. 
Result so far: 25635.85714
If we take 84 away from 90, we end up with 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Moving on to step 12:
If we divide 60 by 21, we get 2 and a remainder of 18.
The number 2 becomes the next digit in our result. 
Result so far: 25635.857142
If we take 42 away from 60, we end up 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.

Step 13:
21 goes into 180 8 times with a remainder of 12.
Put 8 as the next digit of the answer. 
Result so far: 25635.8571428
If we subtract 168 from 180, we 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.

Going ahead to step 14:
120 divided by 21 is 5 with a remainder of 15.
Put 5 as the next digit of the answer. 
Result so far: 25635.85714285
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.

Our division results in 25635.85714285 with a remaining 1.5e-08.