I am a math teacher in a primary school. Now the school lets teachers run interest classes. I have no artistic expertise. What kind of interest classes are suitable for primary school students? these

You can take a photography interest class. Most families have digital cameras or SLR cameras. Pupils are generally not demanding. It doesn't take much effort to learn composition and framing, and finally there is an exhibition.

Or learn to draw beautiful geometric patterns by mathematical methods, which is not only suitable for mathematics, but also close to art, such as how to draw beautiful patterns with dots, or create with protractors and triangles. The painted patterns are processed into exquisite decorative paintings, painted with colors, or turned into small animals, which you can play at will.