805431 ÷ 21 
We're looking to find how many times 21 goes into 805431.

Let's proceed to step 1:
21 can be fit into 8 0 times, resulting in a remainder of 8.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Deduct 0 from 8 and we're left with 8.
Take the next digit (0) from the dividend and append it to 8, then repeat: 80 / 21

Advancing to step 2:
The number 21 fits into 80 3 times, leaving a remainder of 17.
The number 3 becomes the next digit in our result. 
Result so far: 3.0
Subtract 63 from 80 to get 17.
Include the next digit (5) from the dividend after 17, then repeat: 175 / 21

Step 3:
When dividing 175 by 21, we get 8 with a remainder of 7.
Record the quotient 8 as the next digit in the result. 
Result so far: 38.0
Deduct 168 from 175 and we're left with 7.
Include the next digit (4) from the dividend after 7, then repeat: 74 / 21

Going ahead to step 4:
21 can be fit into 74 3 times, resulting in a remainder of 11.
Use 3 as the next digit of our solution. 
Result so far: 383.0
If we subtract 63 from 74, we get 11.
Take the next digit (3) from the dividend and append it to 11, then repeat: 113 / 21

Let's proceed to step 5:
If we divide 113 by 21, we get 5 and a remainder of 8.
The next digit of our result is 5. 
Result so far: 3835.0
Subtract 105 from 113 to get 8.
Append the next digit (1) from the dividend to 8 and continue with: 81 / 21

Going ahead to step 6:
21 goes into 81 3 times with a remainder of 18.
The next digit of our result is 3. 
Result so far: 38353.0
Subtracting 63 from 81 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.

On to step 7:
The number 21 fits into 180 8 times, leaving a remainder of 12.
Use 8 as the next digit of our solution. 
Result so far: 38353.8
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.

Let's proceed to step 8:
21 goes into 120 5 times with a remainder of 15.
Write down 5 as next digit of the result. 
Result so far: 38353.85
If we subtract 105 from 120, we get 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

On to step 9:
The number 21 fits into 150 7 times, leaving a remainder of 3.
Use 7 as the next digit of our solution. 
Result so far: 38353.857
The remainder is 3 after subtracting 147 from 150.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Moving on to step 10:
21 goes into 30 1 times with a remainder of 9.
Put 1 as the next digit of the answer. 
Result so far: 38353.8571
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.

Step 11:
When dividing 90 by 21, we get 4 with a remainder of 6.
Write down 4 as next digit of the result. 
Result so far: 38353.85714
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.

Let's proceed to step 12:
If we divide 60 by 21, we get 2 and a remainder of 18.
Put 2 as the next digit of the answer. 
Result so far: 38353.857142
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.

Advancing to step 13:
If we divide 180 by 21, we get 8 and a remainder of 12.
Use 8 as the next digit of our solution. 
Result so far: 38353.8571428
If we subtract 168 from 180, we get 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Step 14:
21 goes into 120 5 times with a remainder of 15.
Record the quotient 5 as the next digit in the result. 
Result so far: 38353.85714285
If we subtract 105 from 120, we get 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

The quotient of the division is 38353.85714285, and the remainder is 1.5e-08.