Episode 1004


 * Bert sings "I'm Square".


 * Cookie Monster and Ernie: Cookie Monster tells Ernie that he's going on a diet and won't take his cookies, until Grover tells Cookie that he looks sick.


 * David and Maria help Cookie Monster understand the difference between the letters M and N.


 * David measures Big Bird, Grover and some Kids.


 * Two monsters illustrate abierto and cerrado.


 * Song: "Cooperation".