We look at the division of 353769 by 21 
We're looking to find how many times 21 goes into 353769.

Moving on to step 1:
21 goes into 3 0 times with a remainder of 3.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we subtract 0 from 3, we get 3.
Append the next digit (5) from the dividend to 3 and continue with: 35 / 21

On to step 2:
When dividing 35 by 21, we get 1 with a remainder of 14.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
Subtract 21 from 35 to get 14.
Include the next digit (3) from the dividend after 14, then repeat: 143 / 21

Going ahead to step 3:
If we divide 143 by 21, we get 6 and a remainder of 17.
The next digit of our result is 6. 
Result so far: 16.0
If we subtract 126 from 143, we get 17.
Grab the next digit (7) from the dividend, add it to 17, then carry on: 177 / 21

Step 4:
If we divide 177 by 21, we get 8 and a remainder of 9.
The next digit of our result is 8. 
Result so far: 168.0
Subtracting 168 from 177 leaves us with 9.
Grab the next digit (6) from the dividend, add it to 9, then carry on: 96 / 21

On to step 5:
21 can be fit into 96 4 times, resulting in a remainder of 12.
Write down 4 as next digit of the result. 
Result so far: 1684.0
Subtracting 84 from 96 leaves us with 12.
Append the next digit (9) from the dividend to 12 and continue with: 129 / 21

On to step 6:
The number 21 fits into 129 6 times, leaving a remainder of 3.
Write down 6 as next digit of the result. 
Result so far: 16846.0
If we take 126 away from 129, we end up 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.

Let's proceed to step 7:
21 goes into 30 1 times with a remainder of 9.
The number 1 becomes the next digit in our result. 
Result so far: 16846.1
Subtract 21 from 30 to get 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Going ahead to step 8:
21 goes into 90 4 times with a remainder of 6.
The number 4 becomes the next digit in our result. 
Result so far: 16846.14
If we take 84 away from 90, we end up 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.

Moving on to step 9:
When dividing 60 by 21, we get 2 with a remainder of 18.
Put 2 as the next digit of the answer. 
Result so far: 16846.142
Subtracting 42 from 60 leaves us 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.

Let's proceed to step 10:
If we divide 180 by 21, we get 8 and a remainder of 12.
The next digit of our result is 8. 
Result so far: 16846.1428
The remainder is 12 after subtracting 168 from 180.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Advancing to step 11:
The number 21 fits into 120 5 times, leaving a remainder of 15.
Record the quotient 5 as the next digit in the result. 
Result so far: 16846.14285
If we take 105 away from 120, we end up 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 12:
The number 21 fits into 150 7 times, leaving a remainder of 3.
The number 7 becomes the next digit in our result. 
Result so far: 16846.142857
If we take 147 away from 150, we end up 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.

On to step 13:
When dividing 30 by 21, we get 1 with a remainder of 9.
Record the quotient 1 as the next digit in the result. 
Result so far: 16846.1428571
The remainder is 9 after subtracting 21 from 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Moving on to step 14:
The number 21 fits into 90 4 times, leaving a remainder of 6.
The number 4 becomes the next digit in our result. 
Result so far: 16846.14285714
Deduct 84 from 90 and we're left 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.

In conclusion, the division gives 16846.14285714 with a balance of 6e-09.