21355247 divided by 398 
We want to figure out the number of times 21355247 can be divided by 398.

On to step 1:
If we divide 2 by 398, we get 0 and a remainder of 2.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 2 leaves us with 2.
Take the next digit (1) from the dividend and append it to 2, then repeat: 21 / 398

Moving on to step 2:
21 divided by 398 is 0 with a remainder of 21.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
The remainder is 21 after subtracting 0 from 21.
Fetch the next digit (3) from the dividend, attach it to 21 and continue: 213 / 398

Step 3:
The number 398 fits into 213 0 times, leaving a remainder of 213.
The next digit of our result is 0. 
Result so far: 0.0
Subtracting 0 from 213 leaves us with 213.
Grab the next digit (5) from the dividend, add it to 213, then carry on: 2135 / 398

Let's proceed to step 4:
398 can be fit into 2135 5 times, resulting in a remainder of 145.
Put 5 as the next digit of the answer. 
Result so far: 5.0
If we take 1990 away from 2135, we end up with 145.
Append the next digit (5) from the dividend to 145 and continue with: 1455 / 398

Moving on to step 5:
1455 divided by 398 is 3 with a remainder of 261.
Record the quotient 3 as the next digit in the result. 
Result so far: 53.0
Deduct 1194 from 1455 and we're left with 261.
Bring next digit (2) of the dividend behind the 261 and repeat the process: 2612 / 398

On to step 6:
398 goes into 2612 6 times with a remainder of 224.
The number 6 becomes the next digit in our result. 
Result so far: 536.0
If we subtract 2388 from 2612, we get 224.
Bring next digit (4) of the dividend behind the 224 and repeat the process: 2244 / 398

On to step 7:
If we divide 2244 by 398, we get 5 and a remainder of 254.
The number 5 becomes the next digit in our result. 
Result so far: 5365.0
If we take 1990 away from 2244, we end up with 254.
Bring next digit (7) of the dividend behind the 254 and repeat the process: 2547 / 398

Let's proceed to step 8:
If we divide 2547 by 398, we get 6 and a remainder of 159.
Put 6 as the next digit of the answer. 
Result so far: 53656.0
If we take 2388 away from 2547, we end up with 159.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1590, and continue the process.

Step 9:
The number 398 fits into 1590 3 times, leaving a remainder of 396.
The number 3 becomes the next digit in our result. 
Result so far: 53656.3
The remainder is 396 after subtracting 1194 from 1590.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3960, and continue the process.

Moving on to step 10:
3960 divided by 398 is 9 with a remainder of 378.
Use 9 as the next digit of our solution. 
Result so far: 53656.39
The remainder is 378 after subtracting 3582 from 3960.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3780, and continue the process.

On to step 11:
398 goes into 3780 9 times with a remainder of 198.
Put 9 as the next digit of the answer. 
Result so far: 53656.399
If we take 3582 away from 3780, we end up with 198.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1980, and continue the process.

After the division, we end up with 53656.399 and a remainder of 0.0198.