Character mistake: When the Brady kids are practicing for the talent show, instead of saying, "Come on, Pete," Marcia says, "Come on Chris," which is the actor playing Peter's real name (Christopher Knight). (00:14:30)
Character mistake: While they're dancing and practising in the garage Marsha says "come on Chris", when she should have said Peter.
Answer: The dangling bracelet was used for dramatic purposes - to keep the audience on edge.