On January 1, 2011, Gazelle Corporation acquired machinery at a cost of $700,000. Gazelle adopted the double-declining balance method of depreciation for this machinery and had been recording depreciation over an estimated useful life of 10 years, with no residual value. At the beginning of 2013, a decision was made to change to the straight-line method of depreciation for the machinery. what should be the depreciation expense for 2013 ?