Common methods of depreciation are as follows:
Straight Line Depreciation Same depreciation is charged over the entire useful life.
Reducing Balance Depreciation Depreciation expense decreases at a constant rate as the life of an asset progresses.
Sum of the Year' Digits Depreciation Depreciation charge declines by a constant amount as the life of the asset progresses.
Units of Activity Depreciation Depreciation charge varies each period in proportion to the change in level of activity.
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