745
 - 63
	
Start by subtracting the units column. 
The 5 is larger than the 3 so there is no need to borrow.

  745
 - 63	
    2
 
In the ten's column we cannot take 6 away from 4. Since 100 is the same 
as ten 10's we borrow one of the 100's leaving 6 for the hundred's column. 
Since we already have 4 tens, that plus the ten we borrowed now makes 14 
tens for the ten's column. Now the 6 ten's taken away from the 14 tens 
leaves 8 in the tens column.

  614
  745
 + 63	
   82   	

Now all that is left is the hundred's column. There are 6 hundreds left 
and we are going to take away nothing. This still leaves the six hundreds.	

  614
  745
 + 63	
  682   

	

  5859
 + 774	
  

Solution
   715
  5859
 + 774	
  5085