I believe the general rule is that any number which is written with fewer than three words is actually done so. All the cases listed here: http://writing-style

I believe the general rule is that any number which is written with fewer than three words is actually done so. All the cases listed here: http://writing-style-guide.papercheck.com/~paperch1/index.php?title=Expressing_Numbers_MLA http://writing-style-guide.papercheck.com/~paperch1/index.ph...