> You don't say, "I am learning mathematic", unless you are a cretin.

So why is "maths" plural? It's sure as hell not countable. What is "a math"?

At least "mathematic" makes sense—you can deconstruct the morphology to understand this is "a lesson", i.e. the gerund of "to learn". It's also the natural english adjectival form of the greek word.

"maths" is just weird. You might as well use "magicks".

It has an 's' at the end, but it is still treated as a singular noun in most contexts. You don't say "My favorite subjects are mathematics", you say "My favorite subject is mathematics".

This is the wrong place for this debate, but "math" is an abbreviation of "mathematics". Why would you take the end of a word you are abbreviating and add it to your abbreviation? I'll add that "mathematics" is a singular noun.