Math? That would be a considerable stretch.
Linguistics and systematic language learning overlap with many stem topics, such physics (acoustic phonetics), information theory (corpus linguistics), neurophysiology, brain science, experimental psychology (syntax and semantics; mnemonics and other techniques).
On a personal note, many of my posts have a biology or medicine theme, so there is nothing inappropriate about using the #steemstem tag.
RE: Linguistics Is A Science, Not One Of The Humanities 語言學是一門科學,並不屬於人文