First, relational expressions
1, number of copies × number of copies = total number of copies/number of copies = total number of copies/number of copies = number of copies.
2. 1 multiple × multiple = multiple ×××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××
3. Dividend/Divider = quotient dividend/quotient = divisor quotient × divisor = dividend
4. Unit price × quantity = total price ÷ unit price = total quantity ÷ quantity = unit price
5. Work efficiency × working hours = total workload ÷ work efficiency = working hours ÷ total workload ÷ working hours = work efficiency.
6. Appendix+Appendix = sum-one addend = another addend
7. Minus-Minus = Minus-Minus = Minus+Minus = Minus
8. Factor × factor = product ÷ one factor = another factor.
Second, the propulsion speed between units.
1, 1 km = 1 km = 1 km =1000m.
2. 1 m = 10 decimeter 1 decimeter = 1 0cm10mm.
3. 1 m2 = 100 square decimeter 1 square decimeter = 100 square centimeter 1 square centimeter = 100 square millimeter.
4. 1 m3 = 1000 cubic decimeter 1 cubic decimeter = 1000 cubic centimeter 1 cubic centimeter = 1000 cubic millimeter.
5. 1t = 1000kg 1kg = 1000mg = 1kg = 1kg。
6. 1 ha = 10000 m2 1 mu = 666.666 m2.
7. 1 liter = 1 cubic decimeter = 1000 ml 1 ml = 1 cubic centimeter.
Three, geometric shape perimeter area volume calculation formula
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 S=ah÷2.
6. parallelogram area = bottom x height S=ah
7. Trapezoidal area = (upper bottom+lower bottom) × height ÷2 S=(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.
1 1, the surface area of a cuboid = (length× width+length× height+width× height )× 2 formula: S=(a×b+a×c+b×c)×2.
12, cuboid volume = length× width× height formula: V = abh.