Surface Units
Areas of plane figures
 
Surface Units.

In order to express a measurement, you have to indicate its numeric value and the measurement unit in which it is expressed.
Therefore, it is fundemental that you know the surface measurement units.

The principal surface unit is the square metre.
A square metre is the surface of a square whose sides measure one metre.

 Multiples and submultiples of the square metre.
  unit definition equivalent to symbol
multiples square kilometre Square whose sides measure one kilometre 1000000 m2 km2
square hectometre Square whose sides measure one hectometre 10000 m2 hm2
square decametre Square whose sides measure one decametre 100 m2 dam2
principal unit
 square metre Square whose sides measure one metre   m2
submultiples square decimetre Square whose sides measure one decimetre 0.01 m2 dm2
square centimetre Square whose sides measure one centimetre 0.0001 m2 cm2
square millimetre Square whose sides measure one millimetre 0.000001 m2 mm2

You have to take into account that surface units are squared. The step from one unit to the next is made by dividing or multiplying both the length and the width. Therefore, dividing and multiplying by 10 twice means: dividing or multiplying by 100.
 

 

Here are the representation of the square decimetre, the square centimetre and the square millimetre.

You can move the square centimetre and the square millimetre.

-How many square centimetres fit in one square decimetre?

-How many square millimetres fit in one square centimetre?

-How many square millimetres fit in one square decimetre?
         
           
  Eduardo Barbero Corral
 
Spanish Ministry of Education , Social Afairs and Sport. Year 2007
 
 

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