There are many math competitions in junior high schools, but most of them may be competitions in small places. For example, some municipal competitions depend on the importance attached to mathematics in your area. The number of people who participated in the "Hope Cup" and "Hua Cup" math competitions in junior high school in our school is the largest. These two projects should be the most well-known in China and the competition is relatively small. When I participated in the Hope Cup, there were almost 30 first prizes in the city, and the first prizes in the city were almost 10. There seems to be no follow-up competition after winning the Hope Cup. There is also the China Cup National Finals, which are generally held at their own expense. If there is no accident, it will be held in Hua Middle School in Huizhou, Guangdong Province, and the people who go there are generally the top in the country. If I can win the first prize, I feel that the first prize in the senior high school league will be very stable in the future. I only won the third prize in the finals and the second prize in the league in my sophomore year. This national finals is not so hot, but as we all know, personally, the gold content is quite high. It seems that Huabei junior high school can play once, and Hope Cup can play twice. Depending on the year, the Huabei Cup is much more difficult than the Hope Cup.
Then there are some small-scale math competitions, such as the American math competition, which are not well known, but you can practice if you are interested.
Junior high school students are not qualified to take part in the math competition. You can participate if you pay, which is generally divided into preliminaries and semi-finals. Only after the preliminaries can we advance to the semi-finals. If you don't want to make soy sauce, it is recommended to prepare in advance. It is best to study systematically and attend some cram schools. Self-study is basically impossible. The other is to do real questions, and the difficulty of each competition is basically fixed. If you feel comfortable, I suggest reading more about number theory, which is very helpful.
The words of the first couplet are unclear. We don't have this competition here. We usually take part in the league in high school.
I hope it will help you. Good luck and hope to adopt it!