i would like a through work through an explanation please! i struggle with sum of the years digit

Bonita Corp. purchased machinery for $330,000 on May 1,2020 . It is estimated that it will have a useful life of 10 years, salvage value of $16,500, production of 250,800 units, and working hours of 25,000 . During 2021, Bonita Corp. uses the machinery for 2,650 hours, and the machinery produces 27,800 units. From the information given, compute the depreciation charge for 2021 under each of the following methods. (Round intermedlate calculations to 2 decimal places, eg. 5.25 and final answers to 0 decimal ploces, eg. 45,892.)