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First of all, mathematical units

Mathematical units are standards used to measure and measure mathematical concepts and physical quantities. Common mathematical units are length unit, area unit, unit of volume, angle unit, etc.

Units of length include meters, kilometers, centimeters and millimeters; Area units are square meters, square kilometers and square centimeters; Unit of volume includes cubic meters, cubic decimeters and cubic centimeters; Angle units include degrees and radians.

In addition, there are some other common mathematical units and units, such as weight units and time units.

Second, the common names of mathematical units

1. Commonly used units of quantity are: one, ten, hundred, thousand, ten thousand, one hundred thousand, one million, ten million, one billion, ten billion, one hundred billion, one trillion, ten trillion, one hundred trillion, and one gigabyte.

2. Commonly used length units are: kilometer, meter, decimeter, centimeter and millimeter.

3. Common area units are: square millimeter, square centimeter, square decimeter and square meter.

4. Commonly used land area units are: square kilometers, hectares, acres, acres, etc.

5. Commonly used unit of volume are: cubic meter, cubic decimeter and cubic centimeter.

6. Common time units are: hour, minute and second.

7. Commonly used mass units are: tons, kilograms, grams, milligrams, micrograms, etc.

Three. hektare

The hectare is a metric drawing unit. Don't call it square meters or square hectares (easy to remember and convert). The hectare is the metric unit (international unit) of area. A piece of land with an area of one hectare is 10000 square meters.

Area conversion:

1 cm2 = 100 mm2 =0. 1550 in2. 1 square meter = 10000 square centimeter = 1. 1960 square yard.

1 hectare =15mu =10000m2. 1 mu =666.67 square meters.

1 ha =10000m2 = 2.475438+0 1 mu. 1 km2 =100ha = 0.38 1 km2.

1 square inch =6.45 16 square centimeter. 1 square foot = 144 square inch =0.0929 square meter.

1 square yard =9 square feet =0.836 1 square meter. 1 mu =4840 square yards =4046.86 square meters.

1 square mile =640 acres =259.0 hectares.