Words with plural form such as athletics, economics, mathematics, physics, politics, and so on are usually treated as singular.
EXCEPTION:Occasionally some of these words—especially economics, mathematics, politics, and statistics—have plural meanings:
Subject-verb agreement at a glance
When to use the -s (or -es) form of a present-tense verb
Exercises:
Subject-verb agreement 1
Subject-verb agreement 2
Subject-verb agreement 3
Subject-verb agreement 4