When you say "fist to five check" students rate their understanding by holding up the appropriate number of fingers. The goal is for everyone to be in the green. Great way for students to self-assess their understanding and help you to gauge student understanding.
"If you can't control your mouth, there's no way you can hope to control your mind.' This is why right speech is so important in day-to-day practice. In positive terms, right speech means speaking in ways that are trustworthy, harmonious, comforting, and worth taking to heart. When you make a practice of these positive forms of right speech, your words become a gift to others." --Thanissaro Bhikkhu