We divide 239638 by 21
We're looking to find how many times 21 goes into 239638.

Step 1:
2 divided by 21 is 0 with a remainder of 2.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 2, we get 2.
Append the next digit (3) from the dividend to 2 and continue with: 23 / 21

Step 2:
If we divide 23 by 21, we get 1 and a remainder of 2.
Use 1 as the next digit of our solution. 
Result so far: 1.0
The remainder is 2 after subtracting 21 from 23.
Bring next digit (9) of the dividend behind the 2 and repeat the process: 29 / 21

Moving on to step 3:
29 divided by 21 is 1 with a remainder of 8.
Use 1 as the next digit of our solution. 
Result so far: 11.0
The remainder is 8 after subtracting 21 from 29.
Take the next digit (6) from the dividend and append it to 8, then repeat: 86 / 21

Step 4:
86 divided by 21 is 4 with a remainder of 2.
Write down 4 as next digit of the result. 
Result so far: 114.0
Deduct 84 from 86 and we're left with 2.
Include the next digit (3) from the dividend after 2, then repeat: 23 / 21

Moving on to step 5:
When dividing 23 by 21, we get 1 with a remainder of 2.
Record the quotient 1 as the next digit in the result. 
Result so far: 1141.0
Subtract 21 from 23 to get 2.
Fetch the next digit (8) from the dividend, attach it to 2 and continue: 28 / 21

Step 6:
21 can be fit into 28 1 times, resulting in a remainder of 7.
Write down 1 as next digit of the result. 
Result so far: 11411.0
Subtract 21 from 28 to get 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

On to step 7:
The number 21 fits into 70 3 times, leaving a remainder of 7.
Record the quotient 3 as the next digit in the result. 
Result so far: 11411.3
The remainder is 7 after subtracting 63 from 70.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

Let's proceed to step 8:
70 divided by 21 is 3 with a remainder of 7.
The next digit of our result is 3. 
Result so far: 11411.33
If we take 63 away from 70, we end up with 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

After the division, we end up with 11411.33 and a remainder of 0.007.