Images des maths
The website Image des maths gathers expository papers for the lay public. I contributed (in French) the following papers, ordered by increasing difficulty:
"Maths en jean" conference
In April 2013, I gave a talk on the Gauss-Bonnet formula during the 24th "Maths en jean" congress for an of 11 to 15 years old pupils (participating in math circles). One can see this conference (in French) on the this page.