We know that there are 2 methods of depreciation
1.WDV Method (Written down Value Method)
2.SLM Method (Straight Line Method)
WDV Method
Suppose Asset Value is 5000 and Depreciation Rate is 10% WDV.
Depreciation will be computed as follows
Year 1 
Year 2 
Year 3 

Opening Value 
5000 
4500 
4050 
Less Dep 10% 
500 
450 
405 
Closing Value 
4500 
4050 
3645 
Hence Closing Value of One Year becomes opening Value of Next Year on which Depreciation is calculated
Entry Passed
Year 1
Depreciation A/c Dr 500
To Asset 500
Year 2
Depreciation A/c Dr 450
To Asset 450
Year 3
Depreciation A/c Dr 405
To Asset 405
SLM Method
EXAMPLE
Suppose Asset Value is 5000 and Depreciation Rate is 10% SLM.
Depreciation will be computed as follows
Particulars  Year 1  Year 2  Year 3 
Opening Value  5000  4500  4000 
Less Dep 10%  500  500  500 
Closing Value  4500  4000  3500 
Hence, depreciation value is same every year in SLM Method
Entry Passed here also is
Depreciation A/c Dr 500
To Asset 500
Depreciation A/c Dr 500
To Asset 500
Depreciation A/c Dr 500
To Asset 500