first time as a teacher

The head teacher came,into my class and told us all that our teacher a student to teach the class today"Therefore,I am going to choose a student to teach the class today" He said to my surprise, he chose me. So, I went up to the whiteboard and said to my classmate that you needed to listen to me.
I asked them to did the work in the workbook.Then i told them to played the game but quietly.we played game about haft of hour,and then i said "that enough let study".I asked them about grammar but no one answered my question, at that time i was angry and i killed much them !
Less of them I had taken them to the border of Cambodia and fought with the Thai. about 10 of them were killed. This was my student
He was the hero of Cambodia and he didn't die while the wars were coming. At 9:30am i took then back to school.