Let's divide 430886 by 21
Our goal is to divide 430886 by 21.

Step 1:
If we divide 4 by 21, we get 0 and a remainder of 4.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 4 to get 4.
Bring next digit (3) of the dividend behind the 4 and repeat the process: 43 / 21

On to step 2:
When dividing 43 by 21, we get 2 with a remainder of 1.
Put 2 as the next digit of the answer. 
Result so far: 2.0
If we take 42 away from 43, we end up with 1.
Grab the next digit (0) from the dividend, add it to 1, then carry on: 10 / 21

Advancing to step 3:
The number 21 fits into 10 0 times, leaving a remainder of 10.
Write down 0 as next digit of the result. 
Result so far: 20.0
If we take 0 away from 10, we end up with 10.
Grab the next digit (8) from the dividend, add it to 10, then carry on: 108 / 21

Moving on to step 4:
If we divide 108 by 21, we get 5 and a remainder of 3.
Write down 5 as next digit of the result. 
Result so far: 205.0
Subtracting 105 from 108 leaves us with 3.
Fetch the next digit (8) from the dividend, attach it to 3 and continue: 38 / 21

Going ahead to step 5:
When dividing 38 by 21, we get 1 with a remainder of 17.
The next digit of our result is 1. 
Result so far: 2051.0
The remainder is 17 after subtracting 21 from 38.
Bring next digit (6) of the dividend behind the 17 and repeat the process: 176 / 21

Advancing to step 6:
21 can be fit into 176 8 times, resulting in a remainder of 8.
Put 8 as the next digit of the answer. 
Result so far: 20518.0
If we take 168 away from 176, 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.

Moving on to step 7:
21 goes into 80 3 times with a remainder of 17.
Use 3 as the next digit of our solution. 
Result so far: 20518.3
The remainder is 17 after subtracting 63 from 80.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Let's proceed to step 8:
If we divide 170 by 21, we get 8 and a remainder of 2.
The next digit of our result is 8. 
Result so far: 20518.38
Deduct 168 from 170 and we're left with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Moving on to step 9:
21 goes into 20 0 times with a remainder of 20.
Put 0 as the next digit of the answer. 
Result so far: 20518.38
If we subtract 0 from 20, we 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 10:
21 goes into 200 9 times with a remainder of 11.
Use 9 as the next digit of our solution. 
Result so far: 20518.3809
Deduct 189 from 200 and we're left 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.

Going ahead to step 11:
When dividing 110 by 21, we get 5 with a remainder of 5.
Put 5 as the next digit of the answer. 
Result so far: 20518.38095
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.

Advancing to step 12:
21 can be fit into 50 2 times, resulting in a remainder of 8.
The number 2 becomes the next digit in our result. 
Result so far: 20518.380952
If we subtract 42 from 50, we get 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 13:
If we divide 80 by 21, we get 3 and a remainder of 17.
Record the quotient 3 as the next digit in the result. 
Result so far: 20518.3809523
Deduct 63 from 80 and we're left with 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Moving on to step 14:
If we divide 170 by 21, we get 8 and a remainder of 2.
Use 8 as the next digit of our solution. 
Result so far: 20518.38095238
The remainder is 2 after subtracting 168 from 170.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

The final outcome is 20518.38095238, with a leftover of 2e-09.