Type 'easy' or 'hard' to begin the quiz. Easy is a 2-degree grid, hard is a 1-degree grid. Then, try to name the largest UK 1K+ cities in each square IN ORDER. To name a city, you must first click on the grid square to make it have a GREEN border. Then, type in the city answer for that square followed by a '.' (a period).
The squares will start with '0/5' (or maybe fewer cities if less exist in that square). Click on a square and enter the largest city in that square not yet answered (so, the largest city if you have yet to answer a city in that square). You will then have '1/5' and need to click on that square to name the 2nd largest city, and so on until you complete all the cities up to 5 (or less if less exist). If you name an incorrect city in a square it becomes 'locked' and turns red and you can no longer accumulate cities in that square.
You receive 1 point for the largest city in a square, 2 for the 2nd largest, and so on.
At the end of the quiz the largest remaining city you haven't named will be shown in each square.
Quiz Takers 
Helgoland, Koserow and Selfkant aren‘t cities, why are they included on this quiz? Or does it count all municipalities, regardless of their official classification?
they actually are counted as settlements/communes by the German census
It´s usually spelled Heligoland, not Helgoland tho
i’ll change to accept both.
That’s the English spelling, in German it’s Helgoland
On int difficulty, in the square in the northeast around szczecin/stettin, the largest german city is definitely schwedt/oder (33.524 inh.), but it doesn’t accept this nor any other significant town in the region as solution
Found the problem: some towns with “/” in their name are only accepted without it, so “schwedtoder” instead of “schwedt/oder”