Straight Line Depreciation

You know what Depreciation is—you've bought a toilet you think will last 10 years for 500 bucks. At the end of the 10 years, it will be worth zero. (Maybe even less, but let's call it zero for now.) Each year you want to re-value that toilet in case some weird guest comes over and wants to buy it and asks you the price. (Get rid of them fast if you can.) 

If you apply straight line depreciation, then each year you will re-evaluate or re-value the toilet $50 less, so that at the end of 10 years, it shows up as being worth zero on your books. Example: After 3 1/2 years, it's worth $325. Do the math to get there yourself. See Accelerated Depreciation.