WASHINGTON — A coach who crosses himself before a game. A math teacher reads the Bible aloud before the bell rings. A coach who hosts an after-school Christian group in their home.Supreme Court justices discussed all those hypothetical scenarios Monday while hearing arguments about a former public high school football coach from Washington state who wanted to kneel and pray on the field after games. The justices were wrestling with how to balance the religious and free speech rights of teachers and coaches with the …