16178749 divided by 644 
Let's see how many times 644 fits into 16178749.

Step 1:
644 goes into 1 0 times with a remainder of 1.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 1 leaves us with 1.
Fetch the next digit (6) from the dividend, attach it to 1 and continue: 16 / 644

On to step 2:
644 goes into 16 0 times with a remainder of 16.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 16, we get 16.
Bring next digit (1) of the dividend behind the 16 and repeat the process: 161 / 644

Moving on to step 3:
The number 644 fits into 161 0 times, leaving a remainder of 161.
Use 0 as the next digit of our solution. 
Result so far: 0.0
The remainder is 161 after subtracting 0 from 161.
Append the next digit (7) from the dividend to 161 and continue with: 1617 / 644

Going ahead to step 4:
644 can be fit into 1617 2 times, resulting in a remainder of 329.
Record the quotient 2 as the next digit in the result. 
Result so far: 2.0
If we take 1288 away from 1617, we end up with 329.
Take the next digit (8) from the dividend and append it to 329, then repeat: 3298 / 644

On to step 5:
When dividing 3298 by 644, we get 5 with a remainder of 78.
The next digit of our result is 5. 
Result so far: 25.0
If we take 3220 away from 3298, we end up with 78.
Append the next digit (7) from the dividend to 78 and continue with: 787 / 644

Step 6:
If we divide 787 by 644, we get 1 and a remainder of 143.
Write down 1 as next digit of the result. 
Result so far: 251.0
Subtract 644 from 787 to get 143.
Grab the next digit (4) from the dividend, add it to 143, then carry on: 1434 / 644

On to step 7:
644 goes into 1434 2 times with a remainder of 146.
The next digit of our result is 2. 
Result so far: 2512.0
If we take 1288 away from 1434, we end up with 146.
Grab the next digit (9) from the dividend, add it to 146, then carry on: 1469 / 644

On to step 8:
1469 divided by 644 is 2 with a remainder of 181.
Record the quotient 2 as the next digit in the result. 
Result so far: 25122.0
If we subtract 1288 from 1469, we get 181.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1810, and continue the process.

Moving on to step 9:
When dividing 1810 by 644, we get 2 with a remainder of 522.
The number 2 becomes the next digit in our result. 
Result so far: 25122.2
Deduct 1288 from 1810 and we're left with 522.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5220, and continue the process.

Advancing to step 10:
If we divide 5220 by 644, we get 8 and a remainder of 68.
Write down 8 as next digit of the result. 
Result so far: 25122.28
Deduct 5152 from 5220 and we're left with 68.
Since there are no more digits in the dividend, we add a zero to the remainder making it 680, and continue the process.

Going ahead to step 11:
If we divide 680 by 644, we get 1 and a remainder of 36.
Record the quotient 1 as the next digit in the result. 
Result so far: 25122.281
Subtract 644 from 680 to get 36.
Since there are no more digits in the dividend, we add a zero to the remainder making it 360, and continue the process.

On to step 12:
644 can be fit into 360 0 times, resulting in a remainder of 360.
The next digit of our result is 0. 
Result so far: 25122.281
Deduct 0 from 360 and we're left with 360.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3600, and continue the process.

Going ahead to step 13:
The number 644 fits into 3600 5 times, leaving a remainder of 380.
Record the quotient 5 as the next digit in the result. 
Result so far: 25122.28105
Subtracting 3220 from 3600 leaves us with 380.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3800, and continue the process.

On to step 14:
If we divide 3800 by 644, we get 5 and a remainder of 580.
The next digit of our result is 5. 
Result so far: 25122.281055
Deduct 3220 from 3800 and we're left with 580.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5800, and continue the process.

The final outcome is 25122.281055, with a leftover of 5.8e-05.