Mike drags Carol's needlepoint to his side of the bed (the right side), but when Cindy interrupts what Mike and Carol are doing, the needlepoint is on the left side of the bed where Carol originally was.
When Marsha and Doug Simpson are on the hill in the car and he tries to make out with her and she tells him she is not that type of girl, her nose is back to normal, although it was clearly squashed before that scene and all the scenes following.
Mr. Dittmeyer is looking through the driver's side rear view mirror while talking on the car phone. The mirror shows that "objects are closer than they appear" just before Jan knocks off the mirror riding her bicycle. This warning is only on the passenger mirror.
The position of the Greg's guitar strap keeps alternating between being under and over his collar when he's playing for Cindy. The same thing happens moments later when he's playing while watching himself in the mirror.
While walking on his treadmill, Mr Ditmeyer's tomato juice glass is being jarred quite a bit, yet does not fall. After getting off the treadmill to get the Brady's mail, the mere movement of the still-running treadmill belt is enough to make the glass slide off, spilling the juice on the belt indicating the glass was anchored to the console initially.
When Cindy Brady delivers the Dittmeyer's mail, Larry Dittmeyer is running on his treadmill. The Bloody Mary, in the drink holder, has no celery stick in the glass but, in a following close-up, a celery stick appears in the drink from nowhere.
The Brady House, itself a character, as in the TV series, is misrepresented by the photo stills of it between scenes. In the still photos of the Brady house from outside, it does not reveal the upstairs bedrooms in the upper level, which would be in back of the house and to the right, not the left.
In the car, Marcia inserts the 8-track of Davy Jones' solo album on Bell in the tape player and the song "Girl" starts playing. That song, however, does not appear on the album.
Marcia opens her sock drawer with her left hand, but in the next shot, her right hand is seen opening it.
The Brady's try to raise $20,000 to save their house. When Mike and Carol are talking in bed, Mike says to Carol, "Penny for your thoughts." "Twenty thousand of them," which Carol was referring to the money they needed, however, 20,000 pennies is $200, not $20,000. Two million pennies would be $20,000.
Holly calls Peter a "babe". "Babe" was a word used to describe girls and was out of popular usage by the time this movie came out.