We look at the division of 21153335 by 639 
We're looking to find how many times 639 goes into 21153335.

Let's proceed to step 1:
The number 639 fits into 2 0 times, leaving a remainder of 2.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Deduct 0 from 2 and we're left with 2.
Append the next digit (1) from the dividend to 2 and continue with: 21 / 639

Let's proceed to step 2:
If we divide 21 by 639, we get 0 and a remainder of 21.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 21 and we're left with 21.
Include the next digit (1) from the dividend after 21, then repeat: 211 / 639

On to step 3:
The number 639 fits into 211 0 times, leaving a remainder of 211.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 211, we get 211.
Fetch the next digit (5) from the dividend, attach it to 211 and continue: 2115 / 639

Let's proceed to step 4:
The number 639 fits into 2115 3 times, leaving a remainder of 198.
Use 3 as the next digit of our solution. 
Result so far: 3.0
The remainder is 198 after subtracting 1917 from 2115.
Grab the next digit (3) from the dividend, add it to 198, then carry on: 1983 / 639

Going ahead to step 5:
639 can be fit into 1983 3 times, resulting in a remainder of 66.
The number 3 becomes the next digit in our result. 
Result so far: 33.0
Subtracting 1917 from 1983 leaves us with 66.
Include the next digit (3) from the dividend after 66, then repeat: 663 / 639

Step 6:
When dividing 663 by 639, we get 1 with a remainder of 24.
Use 1 as the next digit of our solution. 
Result so far: 331.0
The remainder is 24 after subtracting 639 from 663.
Take the next digit (3) from the dividend and append it to 24, then repeat: 243 / 639

Let's proceed to step 7:
The number 639 fits into 243 0 times, leaving a remainder of 243.
Write down 0 as next digit of the result. 
Result so far: 3310.0
If we take 0 away from 243, we end up with 243.
Grab the next digit (5) from the dividend, add it to 243, then carry on: 2435 / 639

Advancing to step 8:
2435 divided by 639 is 3 with a remainder of 518.
Record the quotient 3 as the next digit in the result. 
Result so far: 33103.0
If we subtract 1917 from 2435, we get 518.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5180, and continue the process.

Going ahead to step 9:
If we divide 5180 by 639, we get 8 and a remainder of 68.
Record the quotient 8 as the next digit in the result. 
Result so far: 33103.8
Subtract 5112 from 5180 to get 68.
Since there are no more digits in the dividend, we add a zero to the remainder making it 680, and continue the process.

Step 10:
639 can be fit into 680 1 times, resulting in a remainder of 41.
The number 1 becomes the next digit in our result. 
Result so far: 33103.81
Deduct 639 from 680 and we're left with 41.
Since there are no more digits in the dividend, we add a zero to the remainder making it 410, and continue the process.

Advancing to step 11:
If we divide 410 by 639, we get 0 and a remainder of 410.
Record the quotient 0 as the next digit in the result. 
Result so far: 33103.81
Deduct 0 from 410 and we're left with 410.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4100, and continue the process.

Advancing to step 12:
The number 639 fits into 4100 6 times, leaving a remainder of 266.
Record the quotient 6 as the next digit in the result. 
Result so far: 33103.8106
Deduct 3834 from 4100 and we're left with 266.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2660, and continue the process.

Advancing to step 13:
639 goes into 2660 4 times with a remainder of 104.
Record the quotient 4 as the next digit in the result. 
Result so far: 33103.81064
If we subtract 2556 from 2660, we get 104.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1040, and continue the process.

Let's proceed to step 14:
639 can be fit into 1040 1 times, resulting in a remainder of 401.
The number 1 becomes the next digit in our result. 
Result so far: 33103.810641
If we take 639 away from 1040, we end up with 401.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4010, and continue the process.

Going ahead to step 15:
639 goes into 4010 6 times with a remainder of 176.
The number 6 becomes the next digit in our result. 
Result so far: 33103.8106416
The remainder is 176 after subtracting 3834 from 4010.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1760, and continue the process.

Moving on to step 16:
The number 639 fits into 1760 2 times, leaving a remainder of 482.
The next digit of our result is 2. 
Result so far: 33103.81064162
If we take 1278 away from 1760, we end up with 482.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4820, and continue the process.

In conclusion, the division gives 33103.81064162 with a balance of 4.82e-07.