[Unfortunately, some of the tutors on here just give the answer 
and don't tell you how they got it.]

You have to make 5 have as many decimals as 1.63 has, which is two
decimals.  So instead of writing 5, put a decimal and two zeros after 
it, like this: 5.00.  Then

    5.00
   -1.63
    3.37

Edwin