valuing opening wip fifo method

Hi My Dear Tutor, I have a question.

In your process accounting lecture video b,you solved the question valuing opening wip fifo method.

At the beginning of July, there were 15000 units of Wip valued as follows
Materials(100%)—-$9000
labor and overhead costs—–$1250
——————————————————-Materials——————-Labor+Ovearheads

finishing to Opening WIP————————————–(60%*15000)—–90000
(15000)

I understood 60% of 15000 because 60% completed of 15000 but coming to materials it says 100% and why we do not recognize 15000 under materials which in the bracket shows 100%.Could you explain this part? please