The success of the MatLan Erasmus + project (2014-2016) and of the eTwinning project Doing Math as Researchers Do It - MatReLan (2016-2017) convinced us that the twinned mathematics research workshops are very good opportunities for transdisciplinary teaching. The ML project intends to develop this approach with (and for) math teachers and foreign language teachers. In this project we will go further in integrating foreign language teaching (EN and FR) to the math research workshops by using a CLIL approach in the math research workshops. The ML project aims to support the 2 partner-schools to: - provide opportunities for the high-school students enrolled in the math research workshop to develop their math, transversal and language skills through collaborative work with students from an EU country; - provide opportunities for math and language teachers to share experiences and improve their CLIL approach. ML is a sub-project of the Maths&Languages Erasmus+ project (2017-2020).