While hurrying to get on the school bus, Arthur and his friend unknowingly switch their lunch boxes; later Arthur finds out what surpise his sister had put into hers.
Frances, who only loves to eat bread and jam, enjoys her favorite food for breakfast, lunch, dinner, and as a snack, but eventually learns that variety is more interesting.
When Thelma tricks Frances into buying her tea set, Frances gets mad! Can Frances show Thelma that it's better to lose a bargain than to lose a friend?
Jealous of her sister's birthday, Frances becomes mean and selfish, until rare generosity and birthday spirit move her to reluctantly give her coveted gift.