This mainly depends on your hobbies. If you really like math, use math to solve problems, preferably in financial engineering. After all, you can enter banks, securities companies and so on. I majored in communication engineering. If you have good hands-on ability and are proficient in electricity, you can also consider communication. The characteristic of communication is a lot of experiments, but once you enter the communication industry, you must study hard and master all the professional knowledge. There will be many similar problems when looking for a job. I don't know if you have heard of Greater China, but Loongson, Datang, ZTE and Huawei. These are China's own four major communication companies in the 1990s. But the dragon's mismanagement has closed down. If you want to find a stable job with study as the main task, go to Datang. Go to Huawei or ZTE if you want to make money in the future. Huawei's induction training is a three-month devil training, which is well-known in the industry. Of course, the employment direction also includes some communication operators such as mobile, telecom and China Unicom.

Generally speaking, the employment of communication is actually quite narrow, and only a few large companies can talk about it, because many communications are confidential and monopolistic. So I personally suggest that if you really like math, there is no need to change it. The communication industry is deep. If you can't be a high-end talent, you will be at the same level as migrant workers. Set up the equipment and bring the optical fiber cable. ...