вче́тверо
adverb
four times; (by) four times (in reference to a quantity, not to occurrences)
увели́чить вче́тверо
quadruple; multiply by four
ACC
something
уме́ньшить вче́тверо
quarter; take a quarter of
ACC
something
вче́тверо ме́ньше
one quarter (of); four times smaller