Problems should use the Courier font. Why? Every Courier font character uses the same amount of space. A comma is the same width as the number 5. This means that all of the numbers line up perfectly for carrying during addition and bringing the zero down in division.
Who's Fault? Is it his fault that he lacks confidence with word problems? Not entirely. Our actions, as educators, seem to imply a belief that solving word problems should come more naturally than simpler operations like arithmetic and algebra. Many parents and teachers feel justified in encouraging (i.e. forcing) a child to work hundreds or thousands of math worksheets, drill multiplication tables, long division... but few encourage solving hundreds of story problems. One suspects that the relative ease of creating and checking ordinary math worksheets keeps the focus of math education on simple, atomic operations at the expense of more holistic story problems.