Top 5 selling singles on iTunes for week ending Dec. 21

December 29, 2010 at 12:00a.m.

Top 5 selling singles on iTunes for week ending Dec. 21:

• “Grenade”: Bruno Mars

• “Firework”: Katy Perry

• “We R Who We R”: Ke$ha

• “What’s My Name?”: Rihanna & Drake

•“Bottoms Up”: (feat. Nicki Minaj) Trey Songz