It was a good question asked by a student today and we used it for the basis of the following problem-solving activity.
The children selected a country that connected with, found the border length on the net and then needed to create a ratio key of what 1 cm would equal for their map.
Sounds simple, but actually a lot of perseverance and thinking was needed in firstly an appropriate ratio and secondly how to draw it using the cm grid lines so that it would shape roughly like the country and match the number of cm needed.
Here are some samples of some students who have already completed their maps:
(This student got mixed up with the ratio as it ought to read: 1cm = 28km)