356830 ÷ 21 
We want to divide 356830 by 21.

Moving on to step 1:
21 goes into 3 0 times with a remainder of 3.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 3 leaves us with 3.
Fetch the next digit (5) from the dividend, attach it to 3 and continue: 35 / 21

On to step 2:
35 divided by 21 is 1 with a remainder of 14.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
If we take 21 away from 35, we end up with 14.
Bring next digit (6) of the dividend behind the 14 and repeat the process: 146 / 21

Advancing to step 3:
21 goes into 146 6 times with a remainder of 20.
Put 6 as the next digit of the answer. 
Result so far: 16.0
If we subtract 126 from 146, we get 20.
Grab the next digit (8) from the dividend, add it to 20, then carry on: 208 / 21

Going ahead to step 4:
21 can be fit into 208 9 times, resulting in a remainder of 19.
Put 9 as the next digit of the answer. 
Result so far: 169.0
Subtracting 189 from 208 leaves us with 19.
Bring next digit (3) of the dividend behind the 19 and repeat the process: 193 / 21

On to step 5:
21 can be fit into 193 9 times, resulting in a remainder of 4.
The number 9 becomes the next digit in our result. 
Result so far: 1699.0
If we subtract 189 from 193, we get 4.
Append the next digit (0) from the dividend to 4 and continue with: 40 / 21

Moving on to step 6:
40 divided by 21 is 1 with a remainder of 19.
Record the quotient 1 as the next digit in the result. 
Result so far: 16991.0
Deduct 21 from 40 and we're left with 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Moving on to step 7:
21 can be fit into 190 9 times, resulting in a remainder of 1.
Put 9 as the next digit of the answer. 
Result so far: 16991.9
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.

Going ahead to step 8:
21 can be fit into 10 0 times, resulting in a remainder of 10.
Write down 0 as next digit of the result. 
Result so far: 16991.9
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 9:
The number 21 fits into 100 4 times, leaving a remainder of 16.
The number 4 becomes the next digit in our result. 
Result so far: 16991.904
Subtract 84 from 100 to 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.

Advancing to step 10:
When dividing 160 by 21, we get 7 with a remainder of 13.
Use 7 as the next digit of our solution. 
Result so far: 16991.9047
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 11:
When dividing 130 by 21, we get 6 with a remainder of 4.
Use 6 as the next digit of our solution. 
Result so far: 16991.90476
Subtract 126 from 130 to get 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Advancing to step 12:
The number 21 fits into 40 1 times, leaving a remainder of 19.
Put 1 as the next digit of the answer. 
Result so far: 16991.904761
Subtracting 21 from 40 leaves us with 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Moving on to step 13:
The number 21 fits into 190 9 times, leaving a remainder of 1.
Put 9 as the next digit of the answer. 
Result so far: 16991.9047619
If we subtract 189 from 190, we get 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Moving on to step 14:
21 goes into 10 0 times with a remainder of 10.
Use 0 as the next digit of our solution. 
Result so far: 16991.9047619
Deduct 0 from 10 and we're left with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

After the division, we end up with 16991.9047619 and a remainder of 1e-08.