Depreciable Assets and Depreciation
　　Depreciation overview
　　计算折旧时，使用X N/12，以防错误。
　　Component depreciation 固定资产的各主要组成部分，分别计提折旧。IFRS要求。
　　Composite/Group depreciation–Averaging the economic lives of a number of property units and depreciating the entire class of assets over a single life.
　　Composite/Group depreciation
　　Averaging the economic lives of a number of property units and depreciating the entire class of assets over a single life.
　　No gain or loss is recognized when one asset in the group is retired
　　Average composite life=Total Depreciable Cost/Biggest Annual Depreciation
　　Average composite rate=1/Average composite life
　　When retired，squeeze “Accu.Depre” instead of G/L
　　Basic Depreciation Methods
　　Straight-line直线法
　　Sum-of-the-Year‘s-Digits年限总和法
　　Declining Balance余额递减法
　　计算中不使用残值
　　用期初的净值按直线法计算折旧后，乘2或1.5
　　Unit-of-Production工作量法
　　Depletion
　　Allocation of the cost of wasting natural resources.
　　Cost of depletion=“REAL”=-Residual Value + Extraction/Development cost+Anticipated restoration cost+Land purchase price
　　Unit depletion=Cost/Estimated recoverable unites
　　Period Depletion=Units X Unit depletion
　　Cost Depletion(GAAP)Vs. % Depletion(F4-52)