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 
I’ve made a few of the neighborhoods a little easier to enter now.
It’s really anoying having to type the articles like “la” and “el” and all names like “La nova esquerra de l’example”, just typing “Esquerra de l’eixample” or similar should be accepted. I lived in Barcelona my whole life and no one says “El poblenou”, it’s just “Poblenou”. Also it didn’t worked “Gràcia” or “Vila de Gràcia”, don’t know why. Very cool anyways! Thanks
Really cool quiz, but I find it impossible to get to 100%. There are some neighbourhoods that for some reason I cannot write with accents or without. Like “el Guinardó”, “el Baix Guinardó”, “Can Baró”, “Torre Baró”, “Baró de Viver”, “Sant Martí de Provençals” and “Provençals de Poblenou”. The issue might be with accents and ç. But then “el Gòtic” or “Vila de Gràcia” are completely fine, so I don’t know…
Furthermore, people generally call the neighbourhoods without the articles “el” and “la” (except maybe three or four), but that’s the official name so… No one can dispute that.
these should work now