How do find out which number you dialed after the call when a contact has multiple numbers associated with it. On an iphone
Go to the Phone app and tap on the Recents tab. You'll see incoming and outgoing calls there. The outgoing calls have a little phone handset icon with an arrow going up. When you click on the information icon, the 'i' inside the circle, you'll see details of the call. It will also say 'incoming' or 'outgoing'.