P22.4 (LO 1, 2, 3) (Error Corrections and Accounting Changes) Penn Company is in the process of adjusting and correcting its books at the end of 2020. In reviewing its records, the following information is compiled.

1. Penn has failed to accrue sales commissions payable at the end of each of the last 2 years, as follows.

December 31, 2019 $3,500

December 31, 2020 $2,500

2. In reviewing December 31, 2020, inventory, Penn discovered errors in its inventory-taking procedures that have caused inventories for the last 3 years to be incorrect, as follows.

December 31, 2018 Understated $16,000

December 31, 2019 Understated $19,000

December 31, 2020 Overstated $ 6,700

Penn has already made an entry that established the incorrect December 31, 2020, inventory amount.

3. At December 31, 2020, Penn decided to change the depreciation method on its office equipment from double-declining-balance to straight-line. The equipment had an original cost of $100,000 when purchased on January 1, 2018. It has a 10-year useful life and no salvage value. Depreciation expense recorded prior to 2020 under the double-declining-balance method was $36,000. Penn has already recorded 2020 depreciation expense of $12,800 using the double-declining-balance method.

4. Before 2020, Penn accounted for its income from long-term construction contracts on the completed-contract basis. Early in 2020, Penn changed to the percentage-of-completion basis for accounting purposes. It continues to use the completed-contract method for tax purposes. Income for 2020 has been recorded using the percentage-of-completion method. The following information is available.

Pretax Income

Percentage-of-Completion Completed-Contract

Prior to 2020 $150,000 $105,000

2020 60,000 20,000

Instructions

Prepare the journal entries necessary at December 31, 2020, to record the above corrections and changes. The books are still open for 2020. The income tax rate is 20%. Penn has not yet recorded its 2020 income tax expense and payable amounts so current-year tax effects may be ignored. Prior-year tax effects must be considered in item 4.