"A problem that I consistently have with MathCAD is when it generates long equations that I need to contain on one page. Does anyone know how to fix this? "
I don't think there's anything you can do about the size of an automatically generated equation; you can use the ctl-+ option to split your own equations at a '+' sign.
Math styles, as pointed out in a previous post, allow you to change the font size, but as Mathcad presents the results in 'Variables' format (plus constants, I think, for numbers), which is the usual default style, changing the font will affect pretty well everything.
Another option is to use Landscape pages - again noting that this will affect the entire worksheet.