Yeah Mädchen as singular is a neutral noun, and as I've just learned, so are all nouns ending with -chen and -lein. Though die is used for feminine nouns like Frau, it is also used for plurals regardless of the subject's gender.
I wrote "the boy like the girls"
The answer is wrong but instead of recognizing the "like" it points to my mistake being in "the girls"
Just thought I'd give a heads up