The mission was simple: to find a coffee shop in Corona, Queens.

The man on the mission was equipped with a large and detailed Hagstrom map, a car with a full tank of gas, a master's degree in economics with a concentration in urban planning and an address from the telephone book. The Yellow Pages listed the coffee shop, El Pasillo, at 37-69 103, Corona.

The first problem for the man, Robert Wood, 34, a math guy from Manhattan who volunteered to try to not get lost in Queens, was the matter of the number 103. The possibilities in Queens for that number are 103rd Street, 103rd Avenue, 103rd Drive and 103rd Road. Ditto for 37 and 69, numbers that Mr. Wood deduced contained crucial information about a cross street (or avenue or drive or road).

In the scheme of things, Mr. Wood had it easy with 103 because other numbered streets in Queens can also be found in the form of places -- as in 65th Place -- as well as lanes, terraces, courts and crescents. Crescents are less common; one of the loveliest crescents, 246th, can be located (although not by Mr. Wood) looping through a fancy nook of northeast Queens, just off 57th Drive, which in that part of Queens is actually the continuation of 244th Street before it becomes 245th Place and then 62nd Avenue.

So at 2:09 p.m. on a recent Saturday, Mr. Wood, his palms only mildly sweaty at this stage, set out for the Corona coffee shop from points west. He got himself onto the Brooklyn-Queens Expressway and exited soon after arriving in Queens, pulling over at 65th Place and Laurel Hill Boulevard in Woodside, about two miles from Corona.