We divide 637423 by 21
We're looking to find how many times 21 goes into 637423.

Step 1:
When dividing 6 by 21, we get 0 with a remainder of 6.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 6 and we're left with 6.
Include the next digit (3) from the dividend after 6, then repeat: 63 / 21

On to step 2:
21 goes into 63 3 times with a remainder of 0.
Use 3 as the next digit of our solution. 
Result so far: 3.0
If we subtract 63 from 63, we get 0.
Append the next digit (7) from the dividend to 0 and continue with: 7 / 21

Step 3:
When dividing 7 by 21, we get 0 with a remainder of 7.
The number 0 becomes the next digit in our result. 
Result so far: 30.0
Subtract 0 from 7 to get 7.
Include the next digit (4) from the dividend after 7, then repeat: 74 / 21

Step 4:
21 goes into 74 3 times with a remainder of 11.
Use 3 as the next digit of our solution. 
Result so far: 303.0
If we subtract 63 from 74, we get 11.
Take the next digit (2) from the dividend and append it to 11, then repeat: 112 / 21

Advancing to step 5:
112 divided by 21 is 5 with a remainder of 7.
Put 5 as the next digit of the answer. 
Result so far: 3035.0
Deduct 105 from 112 and we're left with 7.
Take the next digit (3) from the dividend and append it to 7, then repeat: 73 / 21

Let's proceed to step 6:
21 can be fit into 73 3 times, resulting in a remainder of 10.
The next digit of our result is 3. 
Result so far: 30353.0
The remainder is 10 after subtracting 63 from 73.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

On to step 7:
100 divided by 21 is 4 with a remainder of 16.
Put 4 as the next digit of the answer. 
Result so far: 30353.4
Subtracting 84 from 100 leaves us with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Let's proceed to step 8:
If we divide 160 by 21, we get 7 and a remainder of 13.
Record the quotient 7 as the next digit in the result. 
Result so far: 30353.47
Deduct 147 from 160 and we're left with 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Moving on to step 9:
If we divide 130 by 21, we get 6 and a remainder of 4.
Put 6 as the next digit of the answer. 
Result so far: 30353.476
Deduct 126 from 130 and we're left with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Let's proceed to step 10:
When dividing 40 by 21, we get 1 with a remainder of 19.
Put 1 as the next digit of the answer. 
Result so far: 30353.4761
Subtract 21 from 40 to get 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

On to step 11:
If we divide 190 by 21, we get 9 and a remainder of 1.
Put 9 as the next digit of the answer. 
Result so far: 30353.47619
The remainder is 1 after subtracting 189 from 190.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Advancing to step 12:
The number 21 fits into 10 0 times, leaving a remainder of 10.
Record the quotient 0 as the next digit in the result. 
Result so far: 30353.47619
Subtract 0 from 10 to get 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Let's proceed to step 13:
21 can be fit into 100 4 times, resulting in a remainder of 16.
Put 4 as the next digit of the answer. 
Result so far: 30353.4761904
If we subtract 84 from 100, we get 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Step 14:
When dividing 160 by 21, we get 7 with a remainder of 13.
The number 7 becomes the next digit in our result. 
Result so far: 30353.47619047
If we subtract 147 from 160, we get 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

After the division, we end up with 30353.47619047 and a remainder of 1.3e-08.