American English shortening of mathematics, 1890; the British preference, maths, is attested from 1911. "Math. is used as an abbreviation in written English in the U.K. but not in speech, the normal form being Maths" [OED].
"a mowing, what is gathered from mowing," Old English mæð "mowing, cutting of grass," from Proto-Germanic *mediz (source also of Old Frisian meth, Old High German mad, German Mahd "mowing, hay crop"), from PIE root *me- (4) "to cut down grass or grain." Obsolete except in figurative aftermath.