Let's divide 637835 by 21
We're looking to find how many times 21 goes into 637835.

Advancing to step 1:
21 goes into 6 0 times with a remainder of 6.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 6 to get 6.
Append the next digit (3) from the dividend to 6 and continue with: 63 / 21

Moving on to step 2:
When dividing 63 by 21, we get 3 with a remainder of 0.
The next digit of our result is 3. 
Result so far: 3.0
The remainder is 0 after subtracting 63 from 63.
Include the next digit (7) from the dividend after 0, then repeat: 7 / 21

Advancing to step 3:
21 goes into 7 0 times with a remainder of 7.
The next digit of our result is 0. 
Result so far: 30.0
Deduct 0 from 7 and we're left with 7.
Fetch the next digit (8) from the dividend, attach it to 7 and continue: 78 / 21

Advancing to step 4:
21 can be fit into 78 3 times, resulting in a remainder of 15.
Put 3 as the next digit of the answer. 
Result so far: 303.0
Subtract 63 from 78 to get 15.
Fetch the next digit (3) from the dividend, attach it to 15 and continue: 153 / 21

Let's proceed to step 5:
21 can be fit into 153 7 times, resulting in a remainder of 6.
Put 7 as the next digit of the answer. 
Result so far: 3037.0
Deduct 147 from 153 and we're left with 6.
Include the next digit (5) from the dividend after 6, then repeat: 65 / 21

Moving on to step 6:
21 goes into 65 3 times with a remainder of 2.
Use 3 as the next digit of our solution. 
Result so far: 30373.0
Subtract 63 from 65 to get 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Going ahead to step 7:
21 goes into 20 0 times with a remainder of 20.
The number 0 becomes the next digit in our result. 
Result so far: 30373.0
If we take 0 away from 20, we end up with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Step 8:
21 can be fit into 200 9 times, resulting in a remainder of 11.
Put 9 as the next digit of the answer. 
Result so far: 30373.09
Subtracting 189 from 200 leaves us with 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Going ahead to step 9:
If we divide 110 by 21, we get 5 and a remainder of 5.
Put 5 as the next digit of the answer. 
Result so far: 30373.095
Subtracting 105 from 110 leaves us with 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Advancing to step 10:
21 can be fit into 50 2 times, resulting in a remainder of 8.
Put 2 as the next digit of the answer. 
Result so far: 30373.0952
Subtracting 42 from 50 leaves us with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Going ahead to step 11:
21 goes into 80 3 times with a remainder of 17.
Use 3 as the next digit of our solution. 
Result so far: 30373.09523
Deduct 63 from 80 and we're left with 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

On to step 12:
The number 21 fits into 170 8 times, leaving a remainder of 2.
Write down 8 as next digit of the result. 
Result so far: 30373.095238
If we subtract 168 from 170, we get 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Advancing to step 13:
21 goes into 20 0 times with a remainder of 20.
The number 0 becomes the next digit in our result. 
Result so far: 30373.095238
Subtract 0 from 20 to get 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Going ahead to step 14:
The number 21 fits into 200 9 times, leaving a remainder of 11.
Put 9 as the next digit of the answer. 
Result so far: 30373.09523809
If we subtract 189 from 200, we get 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

The final outcome is 30373.09523809, with a leftover of 1.1e-08.