We look at the division of 21319471 by 644 
Let's see how many times 644 fits into 21319471.

Advancing to step 1:
When dividing 2 by 644, we get 0 with a remainder of 2.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 2 to get 2.
Include the next digit (1) from the dividend after 2, then repeat: 21 / 644

Step 2:
21 divided by 644 is 0 with a remainder of 21.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 21 to get 21.
Grab the next digit (3) from the dividend, add it to 21, then carry on: 213 / 644

Let's proceed to step 3:
The number 644 fits into 213 0 times, leaving a remainder of 213.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we take 0 away from 213, we end up with 213.
Take the next digit (1) from the dividend and append it to 213, then repeat: 2131 / 644

Step 4:
When dividing 2131 by 644, we get 3 with a remainder of 199.
Record the quotient 3 as the next digit in the result. 
Result so far: 3.0
Subtracting 1932 from 2131 leaves us with 199.
Include the next digit (9) from the dividend after 199, then repeat: 1999 / 644

Going ahead to step 5:
644 can be fit into 1999 3 times, resulting in a remainder of 67.
Record the quotient 3 as the next digit in the result. 
Result so far: 33.0
Subtracting 1932 from 1999 leaves us with 67.
Take the next digit (4) from the dividend and append it to 67, then repeat: 674 / 644

Going ahead to step 6:
674 divided by 644 is 1 with a remainder of 30.
The next digit of our result is 1. 
Result so far: 331.0
Subtract 644 from 674 to get 30.
Append the next digit (7) from the dividend to 30 and continue with: 307 / 644

Going ahead to step 7:
When dividing 307 by 644, we get 0 with a remainder of 307.
Put 0 as the next digit of the answer. 
Result so far: 3310.0
Subtracting 0 from 307 leaves us with 307.
Append the next digit (1) from the dividend to 307 and continue with: 3071 / 644

Advancing to step 8:
When dividing 3071 by 644, we get 4 with a remainder of 495.
Record the quotient 4 as the next digit in the result. 
Result so far: 33104.0
If we subtract 2576 from 3071, we get 495.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4950, and continue the process.

On to step 9:
The number 644 fits into 4950 7 times, leaving a remainder of 442.
The number 7 becomes the next digit in our result. 
Result so far: 33104.7
Subtract 4508 from 4950 to get 442.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4420, and continue the process.

Moving on to step 10:
The number 644 fits into 4420 6 times, leaving a remainder of 556.
Record the quotient 6 as the next digit in the result. 
Result so far: 33104.76
Deduct 3864 from 4420 and we're left with 556.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5560, and continue the process.

Going ahead to step 11:
If we divide 5560 by 644, we get 8 and a remainder of 408.
The number 8 becomes the next digit in our result. 
Result so far: 33104.768
If we subtract 5152 from 5560, we get 408.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4080, and continue the process.

Step 12:
The number 644 fits into 4080 6 times, leaving a remainder of 216.
Put 6 as the next digit of the answer. 
Result so far: 33104.7686
Subtracting 3864 from 4080 leaves us with 216.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2160, and continue the process.

On to step 13:
If we divide 2160 by 644, we get 3 and a remainder of 228.
The number 3 becomes the next digit in our result. 
Result so far: 33104.76863
Subtract 1932 from 2160 to get 228.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2280, and continue the process.

Going ahead to step 14:
644 goes into 2280 3 times with a remainder of 348.
The next digit of our result is 3. 
Result so far: 33104.768633
Subtracting 1932 from 2280 leaves us with 348.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3480, and continue the process.

The final outcome is 33104.768633, with a leftover of 3.48e-05.