We look at the division of 906585 by 21 
We're looking to find how many times 21 goes into 906585.

On to step 1:
The number 21 fits into 9 0 times, leaving a remainder of 9.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 9 and we're left with 9.
Append the next digit (0) from the dividend to 9 and continue with: 90 / 21

Let's proceed to step 2:
The number 21 fits into 90 4 times, leaving a remainder of 6.
Put 4 as the next digit of the answer. 
Result so far: 4.0
Subtract 84 from 90 to get 6.
Include the next digit (6) from the dividend after 6, then repeat: 66 / 21

Going ahead to step 3:
If we divide 66 by 21, we get 3 and a remainder of 3.
Put 3 as the next digit of the answer. 
Result so far: 43.0
Subtract 63 from 66 to get 3.
Grab the next digit (5) from the dividend, add it to 3, then carry on: 35 / 21

Step 4:
21 can be fit into 35 1 times, resulting in a remainder of 14.
Use 1 as the next digit of our solution. 
Result so far: 431.0
Subtracting 21 from 35 leaves us with 14.
Include the next digit (8) from the dividend after 14, then repeat: 148 / 21

Step 5:
When dividing 148 by 21, we get 7 with a remainder of 1.
The next digit of our result is 7. 
Result so far: 4317.0
Subtract 147 from 148 to get 1.
Grab the next digit (5) from the dividend, add it to 1, then carry on: 15 / 21

Moving on to step 6:
15 divided by 21 is 0 with a remainder of 15.
The number 0 becomes the next digit in our result. 
Result so far: 43170.0
Deduct 0 from 15 and we're left 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.

On to step 7:
21 goes into 150 7 times with a remainder of 3.
The number 7 becomes the next digit in our result. 
Result so far: 43170.7
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.

Moving on to step 8:
21 can be fit into 30 1 times, resulting in a remainder of 9.
Put 1 as the next digit of the answer. 
Result so far: 43170.71
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.

Moving on to step 9:
21 goes into 90 4 times with a remainder of 6.
Write down 4 as next digit of the result. 
Result so far: 43170.714
Subtracting 84 from 90 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.

Advancing to step 10:
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: 43170.7142
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.

Let's proceed to step 11:
180 divided by 21 is 8 with a remainder of 12.
The next digit of our result is 8. 
Result so far: 43170.71428
Subtract 168 from 180 to 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 12:
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: 43170.714285
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.

Step 13:
21 can be fit into 150 7 times, resulting in a remainder of 3.
Write down 7 as next digit of the result. 
Result so far: 43170.7142857
Deduct 147 from 150 and we're left 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.

Advancing to step 14:
The number 21 fits into 30 1 times, leaving a remainder of 9.
Use 1 as the next digit of our solution. 
Result so far: 43170.71428571
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.

The final result is 43170.71428571 with a remainder of 9e-09.