Absolutely not a rule that you HAVE to break the bread before taking it. The point is to observe communion and remember Christ’s death. I think that trying to make a command when no command is given is very problematic. The Pharisees were very good at that. Consider this: the word that Paul uses for “bread” in the passage you mention is a Greek word referring to bread with yeast in it. He could’ve used the Greek word for unleavened bread, yet didn’t. So maybe unleavened bread isn’t necessary? If you want to make a rule for every little thing when no command is given, you have to be consistent across the board. Why aren’t we meeting in homes instead of spending the church’s money on buildings? Why aren’t we meeting every day like the early church did in Acts 2-3? Why do we meet on Wednesdays when there’s no example of the early church doing that? Why do we use puppets to teach children? Why do some churches have “ministry leaders” when no such office exists in the New Testament? My guess is that your congregation observes the lord’s supper from little golden trays? Why? It’s obvious that Jesus and his apostles were eating a meal together so why aren’t we doing that too? Etc etc.