How do i use the fraction in

fraction tiles 7/8-1/2

I don't really know but i am pretty sure you need to get the same denominators first. So since 2 can go into 8 4 Times, multiply the fraction 1/2 by 4/4 and you will get 4/8. Now subtract 7/8 by 4/8 and you will get 3/8.