In which method of depreciation is the asset depreciated by dividing the depreciable base by the number of years in its estimated life?

The straight-line method of depreciation is characterized by allocating an equal amount of depreciation expense for each year of an asset's useful life. This is achieved by calculating the depreciable base, which is the cost of the asset minus its salvage value, and then dividing that amount by the estimated number of years the asset is expected to be in use. This straightforward approach allows for easy calculation and consistency in financial reporting, making it one of the most commonly used methods of depreciation in accounting.

In contrast, other methods present different strategies for allocating depreciation. The units of production method focuses on usage rather than time, calculating depreciation based on the asset's actual output. The declining balance method accelerates the expense in early years, resulting in higher depreciation earlier on and decreasing amounts as time goes on. Similarly, the sum-of-the-years' digits method accelerates depreciation by applying a formula that emphasizes early years more heavily, leading to a faster rate of write-off than the straight-line approach.

Thus, the straight-line method highlights simplicity and uniformity in expense allocation over the asset's life, making it the correct choice for the question posed.