In Croatia:

http://os-treca-vz.skole.hr/?news_hk=1&news_id=1896&mshow=290#mod_news

In Serbia:

https://osaleksasanticsecanj.nasaskola.rs/vesti/116/eTwinning-projekat

In Concarneau, France:

Students with certifications of participation:

Pi puns in our corridors:

And our website: Projet eTwinning « Let's celebrate Pi Day (and more !!) together ! » - Collège du Porzou à Concarneau (ac-rennes.fr)
 

In Poland: four seasons with pi number

Polish students want Pi stay with us all year so they made some posters. 😀