Should I add my education expenses (materials) if I dropped the class, and had financial aid? The financial aid was only for the tuition and not the additional expenses.

You could, but you would still need to have gone to school at least halftime, so it would depend on whether you attended any other classes or if you only had the dropped class. 

I did attend that semester and finished 6 units. And on my 1098T it says half time. But the class that I paid for the materials I ended up dropping. 

As long as you stayed at least a half time student.