You have two parts to this fraction, you have the " numerator" , " nu-mer-a-tor" , and then you have the bottom part which is the " denominator" , " de-nom-in-at-or" .
Is just the nom de. Well, it's because my British publisher, when the first book came out, thought " this is a book that will appeal to boys" but they didn't want the boys to know a woman had written it.