1 m2 = 100 square decimeter; 1 square decimeter = 100 square centimeter; 1 cm2 = 100 mm2； 1 hectare =10000m2; 1 mu =666.666 m2

Square meter (m_, English: square meter) is the metric unit of area. It is defined as the area of a square with a side length of 1 m. In life, square meters are usually referred to as "square meters" or "squares" for short. Hongkong and Taiwan Province are called "square meters".

When the space occupied by an object is a two-dimensional space, the size of the space occupied is called the area of the object, which can be plane or curved. Square meter, square decimeter and square centimeter are recognized units of area, which can be expressed by letters as (m_, dm_, cm_).