We look at the division of 21488091 by 397 
We want to divide 21488091 by 397.

Advancing to step 1:
The number 397 fits into 2 0 times, leaving a remainder of 2.
The next digit of our result is 0. 
Result so far: 0.0
If we subtract 0 from 2, we get 2.
Fetch the next digit (1) from the dividend, attach it to 2 and continue: 21 / 397

Step 2:
If we divide 21 by 397, we get 0 and a remainder of 21.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we take 0 away from 21, we end up with 21.
Fetch the next digit (4) from the dividend, attach it to 21 and continue: 214 / 397

Going ahead to step 3:
The number 397 fits into 214 0 times, leaving a remainder of 214.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 214 to get 214.
Take the next digit (8) from the dividend and append it to 214, then repeat: 2148 / 397

Moving on to step 4:
397 goes into 2148 5 times with a remainder of 163.
Put 5 as the next digit of the answer. 
Result so far: 5.0
Subtracting 1985 from 2148 leaves us with 163.
Bring next digit (8) of the dividend behind the 163 and repeat the process: 1638 / 397

On to step 5:
If we divide 1638 by 397, we get 4 and a remainder of 50.
Use 4 as the next digit of our solution. 
Result so far: 54.0
If we subtract 1588 from 1638, we get 50.
Fetch the next digit (0) from the dividend, attach it to 50 and continue: 500 / 397

Let's proceed to step 6:
If we divide 500 by 397, we get 1 and a remainder of 103.
The next digit of our result is 1. 
Result so far: 541.0
The remainder is 103 after subtracting 397 from 500.
Append the next digit (9) from the dividend to 103 and continue with: 1039 / 397

On to step 7:
397 can be fit into 1039 2 times, resulting in a remainder of 245.
The next digit of our result is 2. 
Result so far: 5412.0
Subtract 794 from 1039 to get 245.
Include the next digit (1) from the dividend after 245, then repeat: 2451 / 397

Advancing to step 8:
397 goes into 2451 6 times with a remainder of 69.
Use 6 as the next digit of our solution. 
Result so far: 54126.0
Deduct 2382 from 2451 and we're left with 69.
Since there are no more digits in the dividend, we add a zero to the remainder making it 690, and continue the process.

Going ahead to step 9:
If we divide 690 by 397, we get 1 and a remainder of 293.
The number 1 becomes the next digit in our result. 
Result so far: 54126.1
Deduct 397 from 690 and we're left with 293.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2930, and continue the process.

Advancing to step 10:
397 can be fit into 2930 7 times, resulting in a remainder of 151.
The number 7 becomes the next digit in our result. 
Result so far: 54126.17
Subtract 2779 from 2930 to get 151.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1510, and continue the process.

Going ahead to step 11:
397 can be fit into 1510 3 times, resulting in a remainder of 319.
Use 3 as the next digit of our solution. 
Result so far: 54126.173
Subtract 1191 from 1510 to get 319.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3190, and continue the process.

Let's proceed to step 12:
3190 divided by 397 is 8 with a remainder of 14.
The next digit of our result is 8. 
Result so far: 54126.1738
Subtracting 3176 from 3190 leaves us with 14.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

Going ahead to step 13:
397 can be fit into 140 0 times, resulting in a remainder of 140.
Write down 0 as next digit of the result. 
Result so far: 54126.1738
Subtract 0 from 140 to get 140.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1400, and continue the process.

Let's proceed to step 14:
397 goes into 1400 3 times with a remainder of 209.
Put 3 as the next digit of the answer. 
Result so far: 54126.173803
Subtract 1191 from 1400 to get 209.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2090, and continue the process.

Moving on to step 15:
2090 divided by 397 is 5 with a remainder of 105.
Use 5 as the next digit of our solution. 
Result so far: 54126.1738035
If we take 1985 away from 2090, we end up with 105.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1050, and continue the process.

Moving on to step 16:
397 can be fit into 1050 2 times, resulting in a remainder of 256.
The number 2 becomes the next digit in our result. 
Result so far: 54126.17380352
Deduct 794 from 1050 and we're left with 256.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2560, and continue the process.

The final outcome is 54126.17380352, with a leftover of 2.56e-07.