Compute depreciation expense using various depreciation methods.

- The straight-line method allocates an equal amount of the asset's cost to each year of the asset's useful life by dividing the asset's depreciable cost (cost less residual value) by the asset's useful life.

- The declining balance method is an accelerated method of depreciation that produces a declining amount of depreciation expense each period by multiplying the declining carrying value of an asset by a constant depreciation rate (computed as a multiple of the straight-line rate of depreciation).

- The units-of-production method recognizes depreciation expense based on the actual usage of the asset.