624188 ÷ 21 
Our goal is to divide 624188 by 21.

Step 1:
When dividing 6 by 21, we get 0 with a remainder of 6.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 6, we end up with 6.
Fetch the next digit (2) from the dividend, attach it to 6 and continue: 62 / 21

Advancing to step 2:
The number 21 fits into 62 2 times, leaving a remainder of 20.
Record the quotient 2 as the next digit in the result. 
Result so far: 2.0
If we subtract 42 from 62, we get 20.
Take the next digit (4) from the dividend and append it to 20, then repeat: 204 / 21

Moving on to step 3:
204 divided by 21 is 9 with a remainder of 15.
Record the quotient 9 as the next digit in the result. 
Result so far: 29.0
Subtracting 189 from 204 leaves us with 15.
Grab the next digit (1) from the dividend, add it to 15, then carry on: 151 / 21

On to step 4:
The number 21 fits into 151 7 times, leaving a remainder of 4.
Write down 7 as next digit of the result. 
Result so far: 297.0
Subtracting 147 from 151 leaves us with 4.
Append the next digit (8) from the dividend to 4 and continue with: 48 / 21

On to step 5:
48 divided by 21 is 2 with a remainder of 6.
Use 2 as the next digit of our solution. 
Result so far: 2972.0
The remainder is 6 after subtracting 42 from 48.
Bring next digit (8) of the dividend behind the 6 and repeat the process: 68 / 21

Let's proceed to step 6:
21 can be fit into 68 3 times, resulting in a remainder of 5.
Record the quotient 3 as the next digit in the result. 
Result so far: 29723.0
If we take 63 away from 68, we end up 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.

Step 7:
50 divided by 21 is 2 with a remainder of 8.
The next digit of our result is 2. 
Result so far: 29723.2
If we take 42 away from 50, we end up 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.

Advancing to step 8:
21 can be fit into 80 3 times, resulting in a remainder of 17.
Record the quotient 3 as the next digit in the result. 
Result so far: 29723.23
If we subtract 63 from 80, we get 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Step 9:
The number 21 fits into 170 8 times, leaving a remainder of 2.
The number 8 becomes the next digit in our result. 
Result so far: 29723.238
Subtract 168 from 170 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.

On to step 10:
If we divide 20 by 21, we get 0 and a remainder of 20.
Put 0 as the next digit of the answer. 
Result so far: 29723.238
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.

On to step 11:
The number 21 fits into 200 9 times, leaving a remainder of 11.
Write down 9 as next digit of the result. 
Result so far: 29723.23809
If we take 189 away from 200, we end up 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.

On to step 12:
21 can be fit into 110 5 times, resulting in a remainder of 5.
Record the quotient 5 as the next digit in the result. 
Result so far: 29723.238095
Subtract 105 from 110 to get 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Step 13:
50 divided by 21 is 2 with a remainder of 8.
The next digit of our result is 2. 
Result so far: 29723.2380952
The remainder is 8 after subtracting 42 from 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Step 14:
If we divide 80 by 21, we get 3 and a remainder of 17.
Write down 3 as next digit of the result. 
Result so far: 29723.23809523
If we subtract 63 from 80, we get 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

The final result is 29723.23809523 with a remainder of 1.7e-08.