What grade is the rice written in blue?

Fourth grade. By the end of 2022165438+1October 22nd, the word "meter" had been written in the 29th episode of the first volume of the Chinese textbook "Calligraphy Course for Grade Four" for primary schools. Mi, a first-class standardized Chinese character (commonly used word) in China, has an unknown specific time. Some people think that it first appeared in Oracle Bone Inscriptions in Shang Dynasty, and the upper part of its ancient glyph is "meter"; The lower part is like a basket container for rice.