How to add a reference to System.Numerics.dll
http://msdn.microsoft.com/en-us/library/7314433t(v=vs.80).aspx From MSDN: In Solution Explorer, select the project. On the Project menu, choose Add Reference. The Add Reference dialog box opens. Select the tab indicating the type of component you want to reference. In the top pane, select the component you want to reference, and then click the Select button. Press CTRL while clicking … Read more