What a Croc!

A grey plastic crocodile lays on an orange table.
A orange table has a grey plastic crocodile sitting on it, along with a surveyor's wheel. Behind stands two vertical information panels.

It's important to define exactly what is being measured, in order for accurate measurements to be taken.

How it works

Measure a crocodile's back two different ways and compare the results.

Things to try or ask around the exhibit

How long is this crocodile? Measure the crocodile as described both ways on the panel and see whether you get the same result each time.

Background

When making a measurement, it's important to define exactly what is being measured. This makes measurements reliable and comparable.

In this case, a crocodiles's length could be defined as the straight line alongside, or the length across its back including each bump and crevice.

Finding the science in your world

Some measurements are hard to define. For example, how do you find the length of a country's coastline? Do you measure every rock and bump in every cliff face?