Common length units: kilometers (km), meters (m), decimeters (dm), centimeters (cm) and millimeters (mm). (The propulsion rate between adjacent units is 10. )

1 cm = 10 mm 1 decimeter =10cm1m =1decimeter 1 km = 1000 m 2 area.

(1) What is an area? Area is the size of the plane occupied by an object. The measurement of the surface of three-dimensional objects is generally called surface area. (2) Common area unit: square millimeter square centimeter square decimeter square kilometer (3) Conversion of area unit.

1 square centimeter = 100 square millimeter 1 square decimeter = 100 square centimeter/square meter = 1 00 square decimeter 1 inclination = 1000.

(1) What are volume and volume?

Volume is the size of the space occupied by an object.

Volume, the volume of objects that can be accommodated in boxes, oil drums, warehouses, etc. , usually called their volume. (2) Common units

1 unit of volume: cubic meter cubic decimeter cubic centimeter 2 unit of volume: liter milliliter (3) unit conversion.

1 unit of volume: 1 m3 = 1000 cubic decimeter 1 cubic decimeter = 1000 cubic centimeter 2 unit of volume: 1 liter = 1000 ml/kloc-0.

(1) What is quality? Mass means how much an object weighs. (2) Common unit: t kg kg g (3) Common conversion: one ton =1000kg1kg =1000g for five hours.

(1) What is time? It refers to a period of time with a starting point and an ending point.

(2) Common units: century, year, month, day, hour, minute and second.

(3) Unit conversion: 1 century = 100 1 year =365 days (average year), and one year =366 days (leap year).

January, Wednesday, Friday, July, August, October and December are big months, with 3 1 day.

Four, six, nine and eleven are abortions. Abortion lasts for 30 days. In a normal year, February has 28 days. In leap years, February has 29 days. 1 day = 24 hours, 1 hour =60 minutes =60 seconds.

Six currencies

(1) What is money?

Money is a special commodity, which acts as the equivalent of all commodities. Money is a general representative of value and can buy any other commodity. (2) Commonly used unit: Jiao Yuanfen

(3) Unit conversion: 1 yuan = 10 angle = 100 minutes 1 angle = 10 minutes.