You Can't Win 'Em All - S4-E22
Continuity mistake: At the start, when Cindy walks into the kitchen she sets her books down on the counter with the book's binding facing the sink, but in the closeup the book's binding now faces the opposite way, toward the stove. Additionally, the grocery bag which was on the counter right beside Carol, has been moved for the closeup so Carol is in full view, but the bag is now at the very edge of the counter near the stove, which is pretty odd since there's not enough counter there to actually hold the full grocery bag (presumably something else supported the bag off camera). (00:01:30)
You Can't Win 'Em All - S4-E22
Continuity mistake: What appears to be a carton of eggs is sticking out of one of the grocery bags in some shots, but not in others. (00:15:00)
You Can't Win 'Em All - S4-E22
Revealing mistake: When Cindy and her parents get home after the television show, just as Carol and Mike walk down the steps the set's unfinished wood can be seen at the edge of the steps, at the bottom right corner of the screen. (00:22:40)
You Can't Win 'Em All - S4-E22
Continuity mistake: The dress in Cindy's arms turns around from one shot to the next; first the back is facing outward, then the front is. (00:14:15)
Answer: Much trivia has been written about "The Brady Bunch, " including the various interrelationships and dynamics among the members of the cast. For example, much has been written about why Robert Reed's Mike Brady did not appear in a couple of episodes, including the series finale, due to rancorous creative and artistic differences with series creator, Sherwood Schwartz. However, in contrast, I have never run across any reasons given why a particular child did not appear in specific episodes - only that the episodes were missed. This suggests the causes were likely unexceptional, such as illness, injuries, vacations, or real-life family obligations.
Michael Albert
Although those options ARE possible reasons, it just seems a bit ironic that this happened all in Season 2 ONLY and within a short amount of nearly consecutive episodes. Never happened during the other 5 years of the show at all.