The object of this quiz is to adjust each circle's radius so it contains the target population shown at the right but ONLY within Europe. When you click Start you will be shown a marker on a random populated Europe grid square (there are over 90K 10x10 km grid squares used for the data, courtesy of https://human-settlement.emergency.copernicus.eu/index.php). Also you will see an adjustable circle of radius 100 km to start. Adjust the circle's radius by dragging it until it contains the target number of people shown - this target will be between 5 and 100 million people. Then click submit. You are scored on how close your circle's population is to the target.
PLEASE NOTE: ALL of Turkey is included in counting population (not just European portion), and the portion of Russia west of 61.5 degrees E (just east of Chelyabinsk). Nothing outside Europe (such as Africa or middle east other than Turkey) is included toward the population count within a circle.
Quiz Takers 
btw can you also create largest cities per French region quiz? I just want to name cities in Ile-de-France but it’s split into several departments so there’s no convenient way to do it
I think the “Top Cities:” feature is broken on this quiz. I only named 6 cities, and it says I’ve listed the top 1,480 cities. This happens in every department. I am running the latest version of Firefox.
this has been fixed.
tried Seine Saint Denis now and in the 50 hardest table there was
Saint Denis – villetaneuse%
Montreuil – dugny%
and in the missed table all of the other cities (including the previous 2 with the correct city before the %)
it’s because you were the first playing that department.
might be an issue because I’m the first one to take the quiz but for some reason all cities were showing up in the missed list (including the ones I got)