We look at the division of 985821 by 21 
We want to figure out the number of times 985821 can be divided by 21.

Going ahead to step 1:
The number 21 fits into 9 0 times, leaving a remainder of 9.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 9 and we're left with 9.
Append the next digit (8) from the dividend to 9 and continue with: 98 / 21

Advancing to step 2:
If we divide 98 by 21, we get 4 and a remainder of 14.
Write down 4 as next digit of the result. 
Result so far: 4.0
Subtract 84 from 98 to get 14.
Include the next digit (5) from the dividend after 14, then repeat: 145 / 21

Step 3:
The number 21 fits into 145 6 times, leaving a remainder of 19.
Put 6 as the next digit of the answer. 
Result so far: 46.0
Subtracting 126 from 145 leaves us with 19.
Bring next digit (8) of the dividend behind the 19 and repeat the process: 198 / 21

Advancing to step 4:
21 can be fit into 198 9 times, resulting in a remainder of 9.
Use 9 as the next digit of our solution. 
Result so far: 469.0
The remainder is 9 after subtracting 189 from 198.
Grab the next digit (2) from the dividend, add it to 9, then carry on: 92 / 21

Going ahead to step 5:
21 goes into 92 4 times with a remainder of 8.
Use 4 as the next digit of our solution. 
Result so far: 4694.0
The remainder is 8 after subtracting 84 from 92.
Bring next digit (1) of the dividend behind the 8 and repeat the process: 81 / 21

Going ahead to step 6:
21 can be fit into 81 3 times, resulting in a remainder of 18.
The next digit of our result is 3. 
Result so far: 46943.0
The remainder is 18 after subtracting 63 from 81.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Moving on to step 7:
When dividing 180 by 21, we get 8 with a remainder of 12.
Write down 8 as next digit of the result. 
Result so far: 46943.8
Subtracting 168 from 180 leaves us with 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 8:
21 can be fit into 120 5 times, resulting in a remainder of 15.
Put 5 as the next digit of the answer. 
Result so far: 46943.85
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.

Advancing to step 9:
21 can be fit into 150 7 times, resulting in a remainder of 3.
The next digit of our result is 7. 
Result so far: 46943.857
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.

Step 10:
21 can be fit into 30 1 times, resulting in a remainder of 9.
The number 1 becomes the next digit in our result. 
Result so far: 46943.8571
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 11:
When dividing 90 by 21, we get 4 with a remainder of 6.
The next digit of our result is 4. 
Result so far: 46943.85714
If we subtract 84 from 90, we get 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

On to step 12:
21 goes into 60 2 times with a remainder of 18.
Put 2 as the next digit of the answer. 
Result so far: 46943.857142
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.

Moving on to step 13:
21 goes into 180 8 times with a remainder of 12.
The number 8 becomes the next digit in our result. 
Result so far: 46943.8571428
If we take 168 away from 180, we end up with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Going ahead to step 14:
21 goes into 120 5 times with a remainder of 15.
Use 5 as the next digit of our solution. 
Result so far: 46943.85714285
The remainder is 15 after subtracting 105 from 120.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

The final outcome is 46943.85714285, with a leftover of 1.5e-08.