Length unit conversion

1 km = 1 000m1m = 10 decimeter.

1 decimeter =10cm1m =10cm.

1 cm = 10/0mm

Area unit conversion

1 km2 = 100 hectare

1 ha = 1 10,000 m2

1 m2 = 100 square decimeter

1 square decimeter = 100 square centimeter

1 cm2 = 100 mm2

Volume (volume) unit conversion

1 m3 = 1000 cubic decimeter

1 cubic decimeter = 1000 cubic centimeter

1 cubic decimeter = 1 liter

1 cm3 = 1 ml

1 m3 = 1000 liter

Weight unit conversion

1 ton = 1000 kg

1 kg =1000g

1 kg = 1 kg

Rmb unit conversion

1 yuan = 10 angle.

1 angle = 10 point

1 yuan = 100 integral.

Time unit conversion

1 century = 100 1 year = 12

The big month (3 1 day) is: 13578 1065438+ February.

Abortion (30 days) includes: 469 1 1 month.

February 28th in a normal year and February 29th in a leap year.

There is a leap year every four years.

There are 365 days in a normal year and 366 days in a leap year.

1 day =24 hours 1 hour =60 minutes.

1 minute =60 seconds 1 hour =3600 seconds.

Calculation formula of perimeter, area and volume of mathematical geometry in primary schools

1, the perimeter of the rectangle = (length+width) ×2 C=(a+b)×2.

2. The circumference of a square = side length ×4 C=4a.

3. Area of rectangle = length× width S=ab

4. Square area = side length x side length s = a.a = a.

5. Area of triangle = base × height ÷2 2S=ah÷2.

6. parallelogram area = bottom x height S=ah

7. trapezoidal area = (upper bottom+lower bottom) × height ÷ 2s = (a+b) h ÷ 2.

8. Diameter = Radius× 2D = 2r Radius = Diameter ÷2 r=d÷2

9. The circumference of a circle = π× diameter = π× radius× 2c = π d = 2π r.

10, area of circle = π× radius× radius.

Definition theorem formula

Area of triangle = base × height ÷2. The formula S=a×h÷2.

Area of a square = side length × side length formula S=a×a

Area of rectangle = length× width Formula S=a×b

Area of parallelogram = base× height Formula S=a×h

Trapezoidal area = (upper bottom+lower bottom) × height ÷2 Formula S=(a+b)h÷2

Sum of internal angles: sum of internal angles of triangle = 180 degrees.

Cuboid volume = length× width× height formula: V=abh

Volume of cuboid (or cube) = bottom area × height formula: V=abh.

Volume of cube = side length × side length × side length formula: V=aaa.

Circumference = diameter × π formula: L = π d = 2π r

Area of circle = radius × radius× π formula: s = π R2.

Surface (side) area of cylinder: The surface (side) area of cylinder is equal to the perimeter of bottom multiplied by height. Formula: s = ch = π DH = 2π RH.

Surface area of cylinder: the surface area of cylinder is equal to the perimeter of the bottom multiplied by the height plus the area of the circles at both ends. Formula: S=ch+2s=ch+2πr2.

Volume of cylinder: the volume of cylinder is equal to the bottom area multiplied by the height. Formula: V=Sh

Volume of cone = 1/3 bottom× product height. Formula: V= 1/3Sh

Law of fractional addition and subtraction: Fractions with the same denominator are added and subtracted, only the numerator is added and subtracted, and the denominator remains the same. Fractions of different denominators are added and subtracted, first divided, then added and subtracted.

The multiplication of fractions is: use the product of molecules as numerator and the product of denominator as denominator.

The law of division of fractions: dividing by a number is equal to multiplying the reciprocal of this number.