Is it in line with the relevant laws and regulations for primary school teachers to teach mathematics and Chinese together?

There is no clear stipulation that primary school teachers can't work part-time, and the primary school curriculum is not professional enough, so it is possible to teach mathematics in Chinese. It is a common phenomenon that all teachers can teach primary school courses, and it is not enough to go there to see teachers' ability.

Also, a teacher teaches two courses. Do you think teachers only get paid?

How about the book "Higher and Better Mathematical Thinking Methods in Senior High School"?

Enlightenment of mathematical methods

Curriculum arrangement of senior high school entrance examination subjects in Hebei Province

Mathematicians known in primary school and their contributions

An introduction to a painting

According to a school's regulations, students' math final grade consists of three parts: paper grade, group grade and daily performance grade (the proportion of the three parts is as follows)

Bozi 100 points: boys' names have connotation choices.

Qidong Huanggang big examination paper sixth grade second volume mathematics 24. How to do the fifth sub-question of the fourth question in the final exam B?

The positional relationship between circles

Mathematics Outline of College Entrance Examination in Jilin Province