Nouns with a plural form and a singular meaning

Certain nouns have a plural form (ending in -s) but a singular meaning: news; shingles, mumps, rickets; dominoes, billiards, darts etc.:

What's the news?
Shingles is caused by the same virus as chicken pox.
Billiards is a game which connects mathematics and football.

Nouns ending in -ics can either take a singular (if they are considered as the name of a science) or a plural verb (if they express a specific application of the science):

Mathematics was never easy for Tom.
The teacher told him that his mathematics were well below the standard. (his understanding of mathematics or his results)

Rhetorics was one of the seven free arts.
His rhetorics were doing more harm to our case than any mistake we had ever made. (his way of expressing ideas)

Acoustics is the study of sounds.
Poor classroom acoustics create a negative learning environment for many students. (audibility in the classroom)