How to format datagridview to shown correct format number

Hi evryone. 

How can i format datagridview to format decimal number(vat column), to show vat numbers correctly not 1.18 but 18.00. I am storing vat (decimal (4,2) in this format :1.18) . The reason that i am inserting the vat like this, is because during the call up process of data from db to datagriview i need some data to be calculated like: qty*price = subtotal and subtotal/vat=without_vat. 

How should i format the datagridview to show correct format of vat value?