This textbook includes the following contents: addition and subtraction within 100, table multiplication, understanding the length units of centimeters and meters, preliminary understanding of angles, observing objects from different positions and simple symmetry phenomena, simple data sorting methods and one-to-two bar charts, wide-angle mathematics and mathematical practice activities.

The key content of this semester is the addition and subtraction of pen calculation within 100, and the multiplication of tables. This knowledge is the basis for further study, and students should master it effectively. The knowledge of "length unit", "preliminary understanding of angle", "observation object" and "statistics" are also very important, so we should pay enough attention to them in the review process.

Second, review objectives:

The teaching objective of this volume is to enable students to:

1. Master the calculation method of pen addition and subtraction within 100, and be able to calculate correctly. Master the estimation method of adding and subtracting strokes within 100, and realize the diversity of estimation methods.

2. Know the meaning of multiplication and the names of each part in the multiplication formula, memorize all the multiplication formulas and skillfully calculate the multiplication of two one-digit numbers.