20 hectares is 49.42 acres. So about 16 owls could patrol that area (49.42 / 3 = 16.74).

This type of problem is solved using dimensional analysis (also called factor-label method or the unit factor method).

Dimensional analysis is a problem-solving method that uses the fact that any number or expression can be multiplied by one without changing its value.

Often, it is necessary to convert measurements expressed in one unit (such as mm) to another unit (such as cm, m, or km). Such conversions are carried out using conversion factors which are derived from or given in tables in the section on the SI system.

The method of dimensional analysis involves working with these conversion factors and canceling physical units that accompany the numbers or measurements along with the numbers themselves.

See illustrations on how the conversion process is done from links below:

## www.chymist.com

## chem.tamu.edu

Try to solve these Dimensional Analysis Problems from *Vansd.org*.