Because of its popularity, counterfeit copies are common. To ensure you get the genuine, updated guide:
Street vendors selling photocopies or PDF-only versions with missing pages. They are illegal and often contain errors. la guia santillana
The Mexican educational system updates its public school curriculum periodically (most recently with the "Aprendizajes Clave" and the new "Plan de Estudios 2022"). La Guía Santillana is meticulously updated each year to reflect these changes. When a parent or teacher buys the most recent edition, they can be confident that every exercise corresponds directly to the official lessons the child is seeing in the classroom. Because of its popularity, counterfeit copies are common