The double declining balance method is a method of calculating the depreciation of fixed assets based on the frame value (that is, the original value minus the accumulated depreciation). Depreciation of fixed assets is calculated by multiplying the depreciation rate of fixed assets by twice that of the straight-line method, regardless of the net residual value of fixed assets. The double balance reduction method is a method to calculate the depreciation of fixed assets based on the frame value (that is, the value of fixed assets). Excluding the net residual value of the fixed assets, calculate the original value (accumulated depreciation) of the fixed assets at the beginning of each market. Therefore, the double-balanced decline method is also called accelerated depreciation method. In the accelerated depreciation method, to simplify the calculation, the annual depreciation rate is usually calculated and then divided by the 12-month depreciation rate.