1 km = 1000 m？

1 m = 10 decimeter?

1 decimeter = 10/0cm?

1 m = 100 cm？

1 cm = 10/0mm

(2) Weight unit rate:

1 ton = 1000 kg?

1 kg = 1000 g？

1 kg = 1 kg =2 kg?

500g = 1 kg

(3) Monetary unit rate:

RMB unit conversion:

1 yuan = 10 angle?

1 angle = 10 minute?

1 yuan = 100 integral.

(4) addition and subtraction:

Appendix+Appendix = sum?

Addendum sum = another addend

Minus-Minus = Difference?

Minus-Difference = Minus?

Difference+Minus = Minus

(5) perimeter formula:

Square perimeter: side length+side length+side length = perimeter or side length X 4= = perimeter.

Rectangular circumference: length+length+width+width = circumference or (length+width) X 2= = circumference.