Guild Wars 2

So I have 80 of the Fractal relics, but how do I buy ascended gear it says I have 0 on the bottom left.

If you’re talking about your inventory, the bottom left is Gems.

To purchase Ascended rings, you will need to have Pristine Fractal Relics. You earn one per 10+ Daily.

http://wiki.guildwars2.com/wiki/Pristine_Fractal_Relic

The Back pieces cost regular Fractal Relics.