The maths

I've never seen this before. Not only does The Economist freely use the silly word "maths," but they go right ahead and consider it singular.

"The maths is still daunting." article

"Their maths was dodgy..." article

Maybe it's a British thing? Further - and I'm not very good at this - Google turns up tons of entries for "maths is" and "maths was," while results for "maths are" seem to be strictly limited to cases like "Students struggling with maths are going to be put to death." (Okay, not a real example, but fuck it, do the search yourself.)

Not like I care, just strikes me as something I wouldn't find myself saying. Are there any analogous cases of bizarro opposite nouns?