OK, how many of you knew it without looking it up? We don't use them very often except for dates used in the credits of movies and TV shows. OK, there is no reason to turn this into a long, drawn out blog posting so here is the answer. If you draw a line over a Roman numeral, it means to multiply it by one thousand. So if "M" is 1000 than an M with a line over it means to multiply it by 1000 which will give you one million. There, now you know, so have a great day, you hear?