Count von Count sees a plate of muffins at Hooper's Store and counts the muffins, but due to the way they are stacked, The Count misses one. At first, he's upset that he made a mistake, but Alan points out that mistakes happen all the time, which inspires The Count to spend the day counting mistakes. He counts Elmo, who puts his sneakers on the wrong feet, and Oscar, who hangs a "SCRAM!" sign upside down on his trash can. (Although Oscar decides that he likes having the sign upside down, because people have to twist their heads around to read it.) Zoe and Big Bird are building a tower of blocks that falls over, and the Count counts that as a mistake, even though nobody's sure who was responsible.

Meanwhile, Prairie Dawn practices her piano scales, counting up to nine, to the tune of her pageant music. When she comes back later, she sings about the letter Y. She says she's getting better at playing the piano and singing all the time. She comes back for a third and fourth time, singing to the tune of "Oh, Susanna." When she returns for the last time, she makes a mistake, which the Count is happy to count. He reassures her that it's okay to make a mistake when she plays the wrong chord on her piano. Everyone gathers around the piano to sing "The Alphabet Song" as Prairie Dawn plays through the song perfectly.

Segments

• Ben Stiller sings "The People in Your Neighborhood" with Telly Monster, and decides that he'd like to be a person in the neighborhood.
• Cartoon: "Martian Beauty" has nine hairs, nine bows, nine eyes, nine nostrils, nine arms and nine toes. (EKA: Episode 0424)
• Ernie's Show and Tell: Nelson shows Ernie the baby booties he got for his yet-to-be-born sister. (EKA: Episode 3812)
• Film: Wegman's dogs bake bread. (EKA: Episode 3740)
• Worms in Space make the letter Y. (EKA: Episode 3812)

• Elmo's World: Shoes (EKA: Episode 3791)