Joy Cunningham Co. purchased a machine on January 1, 2017, for $550,000. At that time, it was estimated that the machine would have a 10-year life and no residual value. On December 31, 2020, the firm's accountant found that the entry for depreciation expense had been omitted in 2018. In addition, management has informed the accountant that the company plans to switch to straight-line depreciation because of a change in the pattern of the way the asset is used, starting with the year 2020. At present, the company uses the sum-of-the-years'-digits method for depreciating equipment. 

Instructions

Prepare the general journal entries that should be made at December 31, 2020, to record these events. Ignore income tax effects.