k, first of all, a teacher "yelling" at a student for not knowing something is never ok.
second, if I am following you then you want to know what is 10/8*x = 1
if this is it then the answer is 8/10 (the reciprocal) which reduces to 4/5.
Or is it 10/8 as a mixed number? then 10/8 = 5/4
4 goes into 5 with 1 left over so 5/4 = 1 1/4
if this doesn't help, let me know and we'll try again.
Hang in there...math is hard, but if you are willing to work at it, you can get it.