Completing the calculation, the purchase price ($15,000) minus the residual value ($4,500) is $10,500. Divided by seven years of useful life, this gives us an annual depreciation expense of $1,500. This will be the depreciation expense the company recognizes for the equipment every year for the next seven years.
How this calculation appears on the financial statements over time
For the next seven years, the company will recognize an annual depreciation expense of $1,500 on the income statement. At the same time, the book value of the equipment will reduce on the balance sheet by that same $1,500 per year. The reduction in book value is recorded via an account called accumulated depreciation. The chart below summarizes the seven-year accounting life of this equipment.