Why is "n" not adding it's self when i call it in a function?

backup = script.Parent:Clone()
backup.Parent = nil
huma = script.Parent.Humanoid
n = 0.5

huma.Died:Connect(function()
    n += n
    print(n)
    local lolipop = n
    wait(5)
    while lolipop > 0 do    
        backup.Parent = game.Workspace
        lolipop = lolipop - 1
        print(lolipop)
    end
end)

Because you did the arithmetic wrong, you don't add it directly since roblox wont know what to do, instead you would put it equal to it adding by itself, and if its still erroring I would suggest switching the n to a local n.

backup = script.Parent:Clone()
backup.Parent = nil
huma = script.Parent.Humanoid
n = 0.5
	 
huma.Died:Connect(function()
    n = n + n
    print(n)
    local lolipop = n
    wait(5)
	    while lolipop > 0 do   
	        backup.Parent = game.Workspace
	        lolipop = lolipop - 1
	        print(lolipop)
	end
end)