Try this Code,
<div ng-app="" ng-init="ePrice=5">
<asp:Label ID="Label1" runat="server" ng-bind="ePrice"></asp:Label>
<asp:TextBox ID="TextBox1" runat="server" ng-model="Qty"></asp:TextBox>
<asp:Label ID="Label2" runat="server" Text="" ng-bind="ePrice*Qty" ></asp:Label>
</div>