For assets acquired during the year, the sum-of-the-years' digits method requires that the same depreciation rate be used...... (a) for the remaining months of the year of acquisition, then again in the final year of the asset's estimated life for any months not depreciated in Year 1 (b) for 12 consecutive months, even if that results in the same rate being used in two different calendar years. (c) throughout the life of the asset (d) until the end of the calendar year, then recomputed for the next calendar year.