Type 'easy' or 'hard' to begin the quiz. Easy is a 15-degree grid, hard is a 10-degree grid. Then, try to name the largest 50K+ 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 
Itaberaba, Brazil is not working
fixing.
How about adding a 2,500 option (2K5H, as in ‘Two thousand, five hundred’) for those in China, USA, India, etc. so they get cities in countries other than their own and immediate neighbors (for example, someone in the Detroit area using 1k only gets the US, Canada, Mexico, Cuba and a few Caribbean countries)?
Let me put it this way: The 1k option for someone like myself in the Detroit area doesn’t quite reach Los Angeles or Tijuana (but it DOES get San Diego, oddly enough, but NOT Chula Vista!); The San Francisco Bay Area is out of range of anyone east of Fort Wayne.
2,500 would certainly get someone in my area cities in the UK, Ireland, Colombia, Venezuela and Portugal, and likely in Spain, Peru, France, Brazil and Germany.
Okay… so Chula Vista shows up part of the time… because my location tends to drift a little, even though i’m in the same place…