636153 ÷ 21 
Our goal is to divide 636153 by 21.

Advancing to step 1:
21 goes into 6 0 times with a remainder of 6.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 6 after subtracting 0 from 6.
Fetch the next digit (3) from the dividend, attach it to 6 and continue: 63 / 21

Let's proceed to step 2:
If we divide 63 by 21, we get 3 and a remainder of 0.
Write down 3 as next digit of the result. 
Result so far: 3.0
If we take 63 away from 63, we end up with 0.
Bring next digit (6) of the dividend behind the 0 and repeat the process: 6 / 21

Advancing to step 3:
If we divide 6 by 21, we get 0 and a remainder of 6.
Use 0 as the next digit of our solution. 
Result so far: 30.0
Subtracting 0 from 6 leaves us with 6.
Fetch the next digit (1) from the dividend, attach it to 6 and continue: 61 / 21

Let's proceed to step 4:
If we divide 61 by 21, we get 2 and a remainder of 19.
Write down 2 as next digit of the result. 
Result so far: 302.0
Deduct 42 from 61 and we're left with 19.
Append the next digit (5) from the dividend to 19 and continue with: 195 / 21

On to step 5:
21 goes into 195 9 times with a remainder of 6.
Use 9 as the next digit of our solution. 
Result so far: 3029.0
The remainder is 6 after subtracting 189 from 195.
Include the next digit (3) from the dividend after 6, then repeat: 63 / 21

On to step 6:
21 goes into 63 3 times with a remainder of 0.
The number 3 becomes the next digit in our result. 
Result so far: 30293.0
Subtract 63 from 63 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.

Step 7:
When dividing 0 by 21, we get 0 with a remainder of 0.
The next digit of our result is 0. 
Result so far: 30293.0
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.

Moving on to step 8:
When dividing 0 by 21, we get 0 with a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 30293.0
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.

The quotient of the division is 30293.0, and the remainder is 0.0.