The first volume of Grade Two, the first unit length unit: 1, knowing centimeter and meter 2, knowing line segment 2, adding and subtracting unit 2 within 100 (2): 1, adding two digits to two digits (without carry addition) 2, adding two digits to two digits (with carry addition) 3, and subtracting two digits from two digits. Preliminary understanding of unit 3 corner: 1, characteristics of angle 2, understanding of right angle 3, unit test questions, multiplication in unit 4 table (I): 1, preliminary understanding of multiplication 2, multiplication formula of 5 3, multiplication formula of 1, 3 and 4, and multiplication formula of multiplication plus multiplication minus 5 and 6.