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