We're dividing 353835 by 21 
We want to figure out the number of times 353835 can be divided by 21.

Advancing to step 1:
The number 21 fits into 3 0 times, leaving a remainder of 3.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Deduct 0 from 3 and we're left with 3.
Bring next digit (5) of the dividend behind the 3 and repeat the process: 35 / 21

Let's proceed to step 2:
The number 21 fits into 35 1 times, leaving a remainder of 14.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
Subtracting 21 from 35 leaves us with 14.
Fetch the next digit (3) from the dividend, attach it to 14 and continue: 143 / 21

On to step 3:
If we divide 143 by 21, we get 6 and a remainder of 17.
Use 6 as the next digit of our solution. 
Result so far: 16.0
The remainder is 17 after subtracting 126 from 143.
Append the next digit (8) from the dividend to 17 and continue with: 178 / 21

Step 4:
If we divide 178 by 21, we get 8 and a remainder of 10.
Put 8 as the next digit of the answer. 
Result so far: 168.0
The remainder is 10 after subtracting 168 from 178.
Take the next digit (3) from the dividend and append it to 10, then repeat: 103 / 21

Step 5:
21 goes into 103 4 times with a remainder of 19.
Use 4 as the next digit of our solution. 
Result so far: 1684.0
If we take 84 away from 103, we end up with 19.
Fetch the next digit (5) from the dividend, attach it to 19 and continue: 195 / 21

Moving on to step 6:
21 goes into 195 9 times with a remainder of 6.
Record the quotient 9 as the next digit in the result. 
Result so far: 16849.0
Subtracting 189 from 195 leaves us with 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Let's proceed to step 7:
The number 21 fits into 60 2 times, leaving a remainder of 18.
Put 2 as the next digit of the answer. 
Result so far: 16849.2
The remainder is 18 after subtracting 42 from 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Moving on to step 8:
21 goes into 180 8 times with a remainder of 12.
Put 8 as the next digit of the answer. 
Result so far: 16849.28
Subtracting 168 from 180 leaves us with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Let's proceed to step 9:
If we divide 120 by 21, we get 5 and a remainder of 15.
Put 5 as the next digit of the answer. 
Result so far: 16849.285
Subtracting 105 from 120 leaves us with 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Let's proceed to step 10:
If we divide 150 by 21, we get 7 and a remainder of 3.
Use 7 as the next digit of our solution. 
Result so far: 16849.2857
Subtracting 147 from 150 leaves us 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 11:
When dividing 30 by 21, we get 1 with a remainder of 9.
The number 1 becomes the next digit in our result. 
Result so far: 16849.28571
If we take 21 away from 30, we end up 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.

On to step 12:
If we divide 90 by 21, we get 4 and a remainder of 6.
Write down 4 as next digit of the result. 
Result so far: 16849.285714
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.

Advancing to step 13:
When dividing 60 by 21, we get 2 with a remainder of 18.
The next digit of our result is 2. 
Result so far: 16849.2857142
Deduct 42 from 60 and we're left with 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

On to step 14:
21 can be fit into 180 8 times, resulting in a remainder of 12.
Use 8 as the next digit of our solution. 
Result so far: 16849.28571428
If we take 168 away from 180, we end up with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

After the division, we end up with 16849.28571428 and a remainder of 1.2e-08.