Type 'easy' or 'hard' to begin the quiz. Easy is a 5-degree grid, hard is a 2.5-degree grid. Then, try to name the LARGEST city in each grid square which fits the category label for each square. 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). You are given a score from 0 to 100 based on your answer's population compared to the largest city accepted in that square (100 being you named the largest city).
LETTER: means the city starts with that letter.
NUMBER RANGE: (such as 2-5, 10+) means the city contains that many letters (excluding spaces and special characters).
POPULATION RANGE: (such as 50-100K) means the city has that range for its population.
2+ WORDS means the city name has 2 or more words (words denoted by a space or hyphen).
AK and HI are NOT included in this quiz as they often have grid squares with only one answer for this quiz.
At the end of the quiz the largest population missed answer will show in each unanswered square, and for those answered the largest city will be listed if you didn't answer it.
Quiz Takers 
An idea… to facilitate learning from the quiz without having to look everything up, once you’ve made a guess, a hint could show you a descriptor of how close you got “Boiling/Very Hot/Hot/Warm/Cold/Very Cold/ Freezing” or something like that.
Currently there’s no way to know when you make a guess if you were even remotely close, esp. since most of the ones people miss are going to be on the edges of the map. In NYC, if I get something I don’t know it most likely will be in Staten Island, far reaches of Queens or the Bronx. Those places are all far apart, so the next time, I’d be more likely to get in the right area, instead of just randomly clicking around.