I am making a GM command to half palyers hp if they have been misbehaving but some players have odd numbers resulting in decimals. Here is the line, how could I round it off?

mob/GM/verb/Bitchslap(mob/M in world)
set category = "Admin"
world <<"{{[M]}} has recieved a quick bitchslap by [usr]"
M.HP /=2