911921 ÷ 21 
Let's see how many times 21 fits into 911921.

Step 1:
9 divided by 21 is 0 with a remainder of 9.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtracting 0 from 9 leaves us with 9.
Fetch the next digit (1) from the dividend, attach it to 9 and continue: 91 / 21

Let's proceed to step 2:
91 divided by 21 is 4 with a remainder of 7.
Write down 4 as next digit of the result. 
Result so far: 4.0
Deduct 84 from 91 and we're left with 7.
Bring next digit (1) of the dividend behind the 7 and repeat the process: 71 / 21

Going ahead to step 3:
21 can be fit into 71 3 times, resulting in a remainder of 8.
Use 3 as the next digit of our solution. 
Result so far: 43.0
Subtracting 63 from 71 leaves us with 8.
Take the next digit (9) from the dividend and append it to 8, then repeat: 89 / 21

Advancing to step 4:
89 divided by 21 is 4 with a remainder of 5.
Write down 4 as next digit of the result. 
Result so far: 434.0
Deduct 84 from 89 and we're left with 5.
Grab the next digit (2) from the dividend, add it to 5, then carry on: 52 / 21

Moving on to step 5:
21 goes into 52 2 times with a remainder of 10.
The number 2 becomes the next digit in our result. 
Result so far: 4342.0
If we subtract 42 from 52, we get 10.
Include the next digit (1) from the dividend after 10, then repeat: 101 / 21

Step 6:
If we divide 101 by 21, we get 4 and a remainder of 17.
The next digit of our result is 4. 
Result so far: 43424.0
If we subtract 84 from 101, we get 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Advancing to step 7:
21 goes into 170 8 times with a remainder of 2.
The next digit of our result is 8. 
Result so far: 43424.8
If we take 168 away from 170, we end up 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.

Advancing to step 8:
21 can be fit into 20 0 times, resulting in a remainder of 20.
The next digit of our result is 0. 
Result so far: 43424.8
Deduct 0 from 20 and we're left with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Advancing to step 9:
The number 21 fits into 200 9 times, leaving a remainder of 11.
Use 9 as the next digit of our solution. 
Result so far: 43424.809
The remainder is 11 after subtracting 189 from 200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Advancing to step 10:
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: 43424.8095
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.

Going ahead to step 11:
When dividing 50 by 21, we get 2 with a remainder of 8.
The next digit of our result is 2. 
Result so far: 43424.80952
The remainder is 8 after subtracting 42 from 50.
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 12:
When dividing 80 by 21, we get 3 with a remainder of 17.
Put 3 as the next digit of the answer. 
Result so far: 43424.809523
Subtracting 63 from 80 leaves us 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.

On to step 13:
170 divided by 21 is 8 with a remainder of 2.
Use 8 as the next digit of our solution. 
Result so far: 43424.8095238
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.

Step 14:
If we divide 20 by 21, we get 0 and a remainder of 20.
Use 0 as the next digit of our solution. 
Result so far: 43424.8095238
Subtracting 0 from 20 leaves us with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

After the division, we end up with 43424.8095238 and a remainder of 2e-08.