237840 divided by 21 
We're looking to find how many times 21 goes into 237840.

Moving on to step 1:
21 can be fit into 2 0 times, resulting in 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 (3) from the dividend to 2 and continue with: 23 / 21

Advancing to step 2:
When dividing 23 by 21, we get 1 with a remainder of 2.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
Deduct 21 from 23 and we're left with 2.
Include the next digit (7) from the dividend after 2, then repeat: 27 / 21

On to step 3:
27 divided by 21 is 1 with a remainder of 6.
Record the quotient 1 as the next digit in the result. 
Result so far: 11.0
If we take 21 away from 27, we end up with 6.
Append the next digit (8) from the dividend to 6 and continue with: 68 / 21

Let's proceed to step 4:
21 can be fit into 68 3 times, resulting in a remainder of 5.
The next digit of our result is 3. 
Result so far: 113.0
Subtracting 63 from 68 leaves us with 5.
Take the next digit (4) from the dividend and append it to 5, then repeat: 54 / 21

Advancing to step 5:
54 divided by 21 is 2 with a remainder of 12.
The number 2 becomes the next digit in our result. 
Result so far: 1132.0
Subtract 42 from 54 to get 12.
Take the next digit (0) from the dividend and append it to 12, then repeat: 120 / 21

Moving on to step 6:
21 goes into 120 5 times with a remainder of 15.
The next digit of our result is 5. 
Result so far: 11325.0
Subtract 105 from 120 to 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.

Advancing to step 7:
The number 21 fits into 150 7 times, leaving a remainder of 3.
Put 7 as the next digit of the answer. 
Result so far: 11325.7
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 8:
The number 21 fits into 30 1 times, leaving a remainder of 9.
The next digit of our result is 1. 
Result so far: 11325.71
Subtract 21 from 30 to get 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 9:
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: 11325.714
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.

Going ahead to step 10:
21 goes into 60 2 times with a remainder of 18.
Record the quotient 2 as the next digit in the result. 
Result so far: 11325.7142
Subtract 42 from 60 to get 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Going ahead to step 11:
180 divided by 21 is 8 with a remainder of 12.
Write down 8 as next digit of the result. 
Result so far: 11325.71428
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.

Step 12:
21 can be fit into 120 5 times, resulting in a remainder of 15.
Use 5 as the next digit of our solution. 
Result so far: 11325.714285
Subtract 105 from 120 to 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.

On to step 13:
When dividing 150 by 21, we get 7 with a remainder of 3.
Record the quotient 7 as the next digit in the result. 
Result so far: 11325.7142857
If we subtract 147 from 150, we 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.

On to step 14:
If we divide 30 by 21, we get 1 and a remainder of 9.
The number 1 becomes the next digit in our result. 
Result so far: 11325.71428571
Subtracting 21 from 30 leaves us 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.

The final outcome is 11325.71428571, with a leftover of 9e-09.