[adzm]

Both are fine. The singular form "math" is predominant in the States. But, notably, not "mathematic"

[skeezyjefferson]

so is the saying "could care less", but both are wrong and indicative of some kind of low level neurological deficit, possibly lead contamination or something similar

[gizajob]

Maths is the singular form in English speaking countries.

[notorious_pgb]

Not in the US.