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Use of the double-declining balance method results in a decreasing charge to depreciation expense each year. requires that salvage value is not deducted in computing the depreciation base. requires that the book value not be reduced below salvage value. all of these answers are correct. McDonald Company acquired machinery on January 1, 2015 which it depreciated under the straight-line method with an estimated life of fifteen years and no salvage value. On January 1, 2020, McDonald estimated that the remaining life of this machinery was six years with no salvage value. How should this change be accounted for by McDonald? As a prior period adjustment. As the cumulative effect of a change in accounting principle in 2020. By setting future annual depreciation equal to one-sixth of the book value on January 1, 2020. By continuing to depreciate the machinery over the original fifteen year life