protected decimal Calculate(string a, string b)
{
decimal ad = Convert.ToDecimal(a);
decimal bd = Convert.ToDecimal(bd);
if (bd == 0)
{
return 0; // or whatever
}
return ad / bd;
}
<asp:Label ID="lblCalc" runat="server" >
<%# Calculate(Eval("val1").ToString(), Eval("val2").ToString()) %>
</Label>