Scaling according to selected face a complete newbie at blender would very much appreciate some help. 

I did something, and now every time I scale a number of faces, they are scaled according to the main selected face, rather than according to the imaginary middle point between all faces.

I need to get it back to normal, and I have no idea how. 
Please help!
Active element is set as pivot point:



Set it back to "median point".