What's your "teacher number"?

I can't remember what conference I heard this from, but the speaker asked if we knew our "teacher number"... people looked around and thought should I know that, what is that... The speaker said we needed to learn our teacher number because our kids already knew it. Your "teacher number" is the number of times you'll say something before your students know you mean it and they should listen. Do you find yourself giving the same direction 5 times before they all respond? What are ways you could lower your teacher number so you can say things ONCE?