Well, imagine you are playing a game with your friends where you have to solve math problems. Now imagine that instead of just playing with your friends, you go to a big room with other kids who also love math and want to learn more about it.
That's what a French mathematical seminar is like! It's a place where people who love math come together to learn and solve problems together. In these seminars, people often give talks or presentations about math topics, and everyone listens and asks questions to help them understand better.
It's kind of like school, but instead of just learning from a teacher, everyone gets to share their ideas and thoughts about math. And because it's in French, people who speak that language can come together to learn and practice their math skills.
So, basically, a French mathematical seminar is a fun and educational place for people who love math to get together and learn from each other!