In the Phone app (iPhone 5, iOS 6.1.2), I click on a contact's number, the call is initiated and starts ringing.
For a brief moment at this point, the label of the number (home / work / etc…) is displayed alongside the contact's name, but it quickly is removed and replaced with the call timer counting up and only the name (and picture of the contact) are shown.
You can't - in a straight-forward way.
The best work-around is to tap the "Contacts" button on the call screen. This will bring up your list of contacts which you can then select to see the number(s).
The good news: iPhone remembers you position in the contacts when you initiated the call so you don't have to scroll down all the way from "A" contacts.
The bad news: Hopefully you don't have more then one number for a contact. If you do (and most probably do), there is no way to know which of those 2 or 3 numbers you choose when you called the contact.
Interestingly enough, iPhone is nice enough to tell you which (of several under a single contact you are calling) number you are calling when you add a second call. Apparently as of iOS 6.1.3, iPhone no longer does this.
The obvious solution to this isn't palatable due to the amount of work you'd need to do for each contact, but it's to change the way you use the name fields.
Specifically, do not add a second contact number for any contact you must know this information.
So, if you presently have me as a contact:
You would duplicate the contact (optionally linking them or storing them in different groups or even different iCloud accounts) and have three for me.
Again, you have first and last name fields that iOS 6 shows. Furthermore, you would likely come up with a code to shorten @Home to a single character or digit. Finally, I see a legitimate use for emoji.
Based on your preference, you could pick color, shape, density to be very obvious or you could make it very subtle.
Now, this is an awful suggestion if you implement it for all contacts due to the multiplication of work to set it up and then maintain as things change. Worse, if all contacts are tagged, you will have that character or name bleed into other situations.
However, if you only had a few people you needed to know and only tagged their "alternate" numbers and made no other data be in that card, the chance you'd address a Mail envelope or share that contact card would be low and manageable.
Here is a great suggestion (for 50 points).
Just add the numbers in front of the name !
If you want to slow down and have a longer display whom you are calling, add a "pause" after the number.
Go into settings, then go into text,now move the slide bar to the left to make your text smaller. You can leave the bold setting if you like. Now when you go into your contacts, the entire phone number will display. Leaving the slide bar in the center is default and works best.
If your text size is too large, only a few digits appear under the contact name and when you attempt to see the entire number by pressing it or sliding it from right to left, the phone number dials.
Hope This Helps
To see the telephone number, press EDIT, then press the number.
Enter a phone number in the dialer like you normally would. Tap and hold the * key until you're able to select a comma (,). After the comma, add the extension. Save the number into your contacts.
