991242 ÷ 21 
Let's see how many times 21 fits into 991242.

Step 1:
If we divide 9 by 21, we get 0 and a remainder of 9.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 9, we end up with 9.
Fetch the next digit (9) from the dividend, attach it to 9 and continue: 99 / 21

Going ahead to step 2:
When dividing 99 by 21, we get 4 with a remainder of 15.
The number 4 becomes the next digit in our result. 
Result so far: 4.0
Subtract 84 from 99 to get 15.
Bring next digit (1) of the dividend behind the 15 and repeat the process: 151 / 21

Advancing to step 3:
21 can be fit into 151 7 times, resulting in a remainder of 4.
Write down 7 as next digit of the result. 
Result so far: 47.0
If we subtract 147 from 151, we get 4.
Fetch the next digit (2) from the dividend, attach it to 4 and continue: 42 / 21

Moving on to step 4:
When dividing 42 by 21, we get 2 with a remainder of 0.
The number 2 becomes the next digit in our result. 
Result so far: 472.0
Subtract 42 from 42 to get 0.
Fetch the next digit (4) from the dividend, attach it to 0 and continue: 4 / 21

Moving on to step 5:
21 can be fit into 4 0 times, resulting in a remainder of 4.
The next digit of our result is 0. 
Result so far: 4720.0
Deduct 0 from 4 and we're left with 4.
Append the next digit (2) from the dividend to 4 and continue with: 42 / 21

On to step 6:
42 divided by 21 is 2 with a remainder of 0.
Use 2 as the next digit of our solution. 
Result so far: 47202.0
If we subtract 42 from 42, we get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Advancing to step 7:
When dividing 0 by 21, we get 0 with a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 47202.0
The remainder is 0 after subtracting 0 from 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Advancing to step 8:
21 can be fit into 0 0 times, resulting in a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 47202.0
If we take 0 away from 0, we end up with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

The final result is 47202.0 with a remainder of 0.0.