We look at the division of 15736231 by 644 
We're looking to find how many times 644 goes into 15736231.

Moving on to step 1:
The number 644 fits into 1 0 times, leaving a remainder of 1.
The next digit of our result is 0. 
Result so far: 0.0
If we take 0 away from 1, we end up with 1.
Append the next digit (5) from the dividend to 1 and continue with: 15 / 644

Let's proceed to step 2:
15 divided by 644 is 0 with a remainder of 15.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 15 after subtracting 0 from 15.
Fetch the next digit (7) from the dividend, attach it to 15 and continue: 157 / 644

Moving on to step 3:
644 goes into 157 0 times with a remainder of 157.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 157 after subtracting 0 from 157.
Fetch the next digit (3) from the dividend, attach it to 157 and continue: 1573 / 644

Let's proceed to step 4:
The number 644 fits into 1573 2 times, leaving a remainder of 285.
Record the quotient 2 as the next digit in the result. 
Result so far: 2.0
The remainder is 285 after subtracting 1288 from 1573.
Take the next digit (6) from the dividend and append it to 285, then repeat: 2856 / 644

Going ahead to step 5:
The number 644 fits into 2856 4 times, leaving a remainder of 280.
Use 4 as the next digit of our solution. 
Result so far: 24.0
Subtracting 2576 from 2856 leaves us with 280.
Append the next digit (2) from the dividend to 280 and continue with: 2802 / 644

On to step 6:
2802 divided by 644 is 4 with a remainder of 226.
Use 4 as the next digit of our solution. 
Result so far: 244.0
Deduct 2576 from 2802 and we're left with 226.
Grab the next digit (3) from the dividend, add it to 226, then carry on: 2263 / 644

On to step 7:
644 can be fit into 2263 3 times, resulting in a remainder of 331.
The number 3 becomes the next digit in our result. 
Result so far: 2443.0
If we take 1932 away from 2263, we end up with 331.
Append the next digit (1) from the dividend to 331 and continue with: 3311 / 644

Step 8:
644 can be fit into 3311 5 times, resulting in a remainder of 91.
Use 5 as the next digit of our solution. 
Result so far: 24435.0
The remainder is 91 after subtracting 3220 from 3311.
Since there are no more digits in the dividend, we add a zero to the remainder making it 910, and continue the process.

Step 9:
644 goes into 910 1 times with a remainder of 266.
The number 1 becomes the next digit in our result. 
Result so far: 24435.1
Subtract 644 from 910 to get 266.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2660, and continue the process.

Let's proceed to step 10:
The number 644 fits into 2660 4 times, leaving a remainder of 84.
Use 4 as the next digit of our solution. 
Result so far: 24435.14
Deduct 2576 from 2660 and we're left with 84.
Since there are no more digits in the dividend, we add a zero to the remainder making it 840, and continue the process.

On to step 11:
840 divided by 644 is 1 with a remainder of 196.
Use 1 as the next digit of our solution. 
Result so far: 24435.141
If we subtract 644 from 840, we get 196.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1960, and continue the process.

Moving on to step 12:
When dividing 1960 by 644, we get 3 with a remainder of 28.
Use 3 as the next digit of our solution. 
Result so far: 24435.1413
Subtracting 1932 from 1960 leaves us with 28.
Since there are no more digits in the dividend, we add a zero to the remainder making it 280, and continue the process.

Step 13:
When dividing 280 by 644, we get 0 with a remainder of 280.
The number 0 becomes the next digit in our result. 
Result so far: 24435.1413
If we subtract 0 from 280, we get 280.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2800, and continue the process.

Advancing to step 14:
If we divide 2800 by 644, we get 4 and a remainder of 224.
Put 4 as the next digit of the answer. 
Result so far: 24435.141304
If we subtract 2576 from 2800, we get 224.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2240, and continue the process.

Let's proceed to step 15:
644 goes into 2240 3 times with a remainder of 308.
Record the quotient 3 as the next digit in the result. 
Result so far: 24435.1413043
Deduct 1932 from 2240 and we're left with 308.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3080, and continue the process.

Moving on to step 16:
644 goes into 3080 4 times with a remainder of 504.
Use 4 as the next digit of our solution. 
Result so far: 24435.14130434
Deduct 2576 from 3080 and we're left with 504.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5040, and continue the process.

The final outcome is 24435.14130434, with a leftover of 5.04e-07.