The Skype app lets you make free voice calls from your Surface to another Surface, PC, or almost any other type of computer gadget. But if you want to call a real telephone number — a landline — you need to pay with real money. That’s where Skype Credits come in. You buy them in advance and then use them on a per-minute basis as you talk to somebody on their landline.

The first time you try to dial a real phone number, Microsoft offers you a chance to buy Skype Credits. But before paying up, take advantage of the free one-year Skype subscription that came with your Surface 2 or Surface Pro 2.

To dial a real phone number with Skype, follow these steps:

  1. Start Skype with a tap on its Start screen tile.

  2. Tap the New Call icon in the screen’s upper-left corner; when the numeric keypad appears, tap in the number you want to call.

    If you’re calling somebody in a country other than your own, first choose that country from the drop-down list above the keypad.

After you dial the number, the experience is much like a “real” phone. You hear the sound of the other phone ringing, and then you hear either the happy voice of your friend or the robotic voice of her answering machine.