There is 12 unit before the mid-term exam in the first volume of seventh grade mathematics. According to the relevant information, the one-dimensional linear inequality equation of unit 12 is obtained in the middle-term examination of junior one mathematics, so the middle-term examination of junior one mathematics in grade seven has unit 12. Mid-term examination is an examination to test students' knowledge learned in half a semester, which is conducive to students' formal test of their usual learning level. According to this achievement, students can adjust their learning mentality and methods in time and carry out the next stage of learning more efficiently. The mid-term exam mainly examines students' academic performance in the first half of the semester.