What do 13 year olds do in math?

I'm curious, what kind of mathematical activities do 13 year olds typically engage in? Are they still mastering basic arithmetic skills or have they progressed to more complex concepts like algebra and geometry? Do they have access to interactive math tools and software that can make learning more engaging and effective? And what role does their teacher play in guiding them through these mathematical challenges? I'd love to hear more about the types of math that 13 year olds are working on and how they're approaching it.