How do i use for x= 9,5, -1?

I currently have use it in many things

for x = 10,0, -1
print(x)
end

My current plan is to make it as a countdown? But it just goes: 10,9,8,7..etc. Instead of 10..9...8, Can anybody help me?

You can add a delay like this:

for x = 10,0, -1 do
	print(x)
	wait(0.1)
end

Where 0.1 is the length of the delay, in seconds.