The Challenge: Create a Scale Map 
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Mapping involves measuring angles and distances. Without any rulers, we first needed to define some unit of measurement for length. We could have just used some arbitrary unit, such as an arm length, as a standard distance. But then we would have had to give all the distances in terms of this length, so a mountain might be 2000 'arm lengths' away. We decided we'd try to get an estimate for a meter instead.
How can we measure a meter?
We relied on the fact that most people (in countries that use the metric system, at least) know their own height to within a centimeter. So we measured each of the Rough Scientists in turn and from these figures deduced what a meter length would be.
Height lineup
How do we measure long distances?
