In finding the depreciation charge, why is it in the sum of years digit method use the 5 value in the reverse digit? Thank you in advance for the positive response.

6. A telephone company purchased a microwave radio equipment for P6,000,000. Freight and installation charges amounted to 3% of the purchase price. If the equipment shall be depreciated over a period of 8 years with a salvage value of 5%, determine the following: (a) Annual depreciation charge using the straight line method. (b) Depreciation charge during the fifth year using the sum-ofthe-years-digits method. Ans. (a) P733,875 (b) P652,333