Upon clicking START you’ll be shown a Europe city and a population slider below it. Move the slider to the city’s population and click SUBMIT. You’ll get a score from 0 to 100 based on how accurate your guess was. Complete 20 random cities from among the 200 largest Europe cities to end the quiz. You won’t get more than 3 cities from a single country.

If you click on the slider you can use the left and right arrows to move it more accurately.