Open the Chrome browser and go to the tab you want to cast. 

Click the three dots (More) in the top-right corner of the browser window. 

From the dropdown menu, hover over "Cast, save, and share," and then click Cast. 

Select the cast receiver (your TV with your room number) from the list (e.g., GMS-111, GMS-8112, GHS-130, GHS-151)

The tab will now appear on your TV. To stop, click the cast icon that appears in the toolbar and select Stop casting. 

To share your entire screen select (Sources) then click (Cast screen) and finally select your room number.