In her never ending quest to climb out of the doldrums of being the middle child, Debbie takes up playing the tuba.
Tom introduces a young man to the world of real estate by taking him along as he tries to sell a property to one small business while convincing another small business to move into the vacated space. The situation gets out of hand (as usual).
Frustrated by having the phone constantly tied up, Tom asks the phone company about installing a pay phone. When he finds out that only a commercial location can have a pay phone, he claims that his house is a boarding house. The deception goes further when Tom lures a promising out-of-town client into staying at the ""boarding house"". Tom's family must now play the role of fellow boarders.
In another scheme to lift Debbie out of ""middlechilditis"", Tom helps her to prepare to compete in the national spelling bee. Spelling gags abound.
Tom's family spends entirely too much money. To enforce discipline, he puts Fran and the girls, and his mother-in-law on a ""strict cash basis"". It backfires, though, when Tom takes a client to lunch and can't pay the check because he doesn't have the cash, and he has cut off the charge cards and checking account. Trying to withdraw cash from the bank, Tom is mistakenly thought to be committing a robbery.