**1. Do the divisions on a scale always have to be equal?**

No, it is possible to have a

non-uniformscale.Examples of non-uniform scales are the scale that measures earthquakes (the Richter scale) and scales on radio dials.

e.g. On the Richter scale of earthquakes which goes from 1 to 8. An earthquake of magnitude 8, which is a great earthquake is not twice as severe as an earthquake of magnitude 4 (slight damage within a small area). It is much more serious.

**2. Why is it so important to put the units next to values in tables?**

Although it is sometimes obvious what the units are, there can be confusion. e.g. Is the time

amorpm?Is the dollar value in

USdollars orNZdollars?Is the temperature in degrees

centigradeor degreesfarenheit?Many countries use metric units but some still use older systems.