We express
the distance in kilometres when it is large, such as the distance between
two towns.
We express
the distance in millimetres when it is small, such as the thickness of
a pencil.
The same measurement
can be expressed in any unit but we have to use the most suitable unit.
Besides, we sometimes have to add or subtract several measurements. In order to do this, they have to be expressed in the same unit, that is why it is fundamental to know how to convert units.


The series
of length units work in the same way as the units of our numeration system.
Each
unit has a value ten times larger than the unit on the right and ten times
smaller than the unit on the left.
You
have to notice in which direction the unit jumps in order to move the
decimal point in the same way.
This
activity shows a measurement expressed in a certain unit and on
the right you will find the unit to do the conversion.
Type
the resulting number in the small window below.
After
typing the number hit Enter.
If
your answer is correct, this number will appear. If it isn't, try
again.

When you click
on Init, a different activity will appear. Do several conversions until you master unit
conversion. 