355824 divided by 21 
We want to figure out the number of times 355824 can be divided by 21.

Advancing to step 1:
21 can be fit into 3 0 times, resulting in a remainder of 3.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we take 0 away from 3, we end up with 3.
Include the next digit (5) from the dividend after 3, then repeat: 35 / 21

On to step 2:
35 divided by 21 is 1 with a remainder of 14.
Put 1 as the next digit of the answer. 
Result so far: 1.0
The remainder is 14 after subtracting 21 from 35.
Append the next digit (5) from the dividend to 14 and continue with: 145 / 21

Step 3:
The number 21 fits into 145 6 times, leaving a remainder of 19.
Record the quotient 6 as the next digit in the result. 
Result so far: 16.0
If we subtract 126 from 145, we get 19.
Grab the next digit (8) from the dividend, add it to 19, then carry on: 198 / 21

Step 4:
The number 21 fits into 198 9 times, leaving a remainder of 9.
Put 9 as the next digit of the answer. 
Result so far: 169.0
Subtract 189 from 198 to get 9.
Bring next digit (2) of the dividend behind the 9 and repeat the process: 92 / 21

Let's proceed to step 5:
When dividing 92 by 21, we get 4 with a remainder of 8.
Write down 4 as next digit of the result. 
Result so far: 1694.0
Subtracting 84 from 92 leaves us with 8.
Take the next digit (4) from the dividend and append it to 8, then repeat: 84 / 21

Moving on to step 6:
84 divided by 21 is 4 with a remainder of 0.
Put 4 as the next digit of the answer. 
Result so far: 16944.0
Subtracting 84 from 84 leaves us with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Step 7:
If we divide 0 by 21, we get 0 and a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 16944.0
Subtracting 0 from 0 leaves us with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Let's proceed to step 8:
The number 21 fits into 0 0 times, leaving a remainder of 0.
The next digit of our result is 0. 
Result so far: 16944.0
Deduct 0 from 0 and we're left with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

The quotient of the division is 16944.0, and the remainder is 0.0.