font size

Hi there! iPad 2 Mini is my first iPad. While I did expect version 7 of iOS, it came with version 10.0.2 I heard that the earlier versions are faster and newer versions make this model slower which prompted me to find out if I can downgrade to earlie versions. It seems that I can't actually...

I have read how to change the font size and margins however even when I tap on the screen I do not have the "Aa" icon in the tool bar at the top, (only a brightness control, the notebook & flashcard icons). My iPad is an iPad 2, I have the latest iOS update and my Kindle app is fully updated...