we have adjusted entries the office furniture was purchased on march 1 2010 and has estimated useful life of two years after two years of use is expected that the furniture will be worthless we have October 31 2011 unjusted trial balance said 61450 office furniture so the calculation was 61450/2 = 30720 and we posted like that in the general journal and ledger why? ps 30720 was the right amount but why we don't calculate the months ??