If I start setting up a trip on the Amtrak webpage, I see an icon for the "roomette". Right under that Icon there is a number which is usually "1" or "2". There is a minus sign to the left of that number and a plus sign to the right of that number. Sometimes, but not always, hitting the minus sign will decrease that number and hitting the plus sign will increase that number. What does that number mean? I see no explanation shown for it on the Amtrak webpage for setting up trips.