Black Holes. Don't let the name fool you: a black hole is anything but empty space. Rather, it is a great amount of matter packed into a very small area - think of a star ten times more massive than the Sun squeezed into a sphere approximately the diameter of New York City.
Determine Census Tract Codes Based on Address. â¢ Key in an address here to find codes/names based on address. Census tracts within a county are identified by a 4-digit basic code between 0001 and 9999, and may have a 2-digit suffix ranging from .01 to .98; for example, 6059.02. The decimal point separating the 4-digit basic tract code from the 2-digit suffix is shown in U.S. Census Bureau printed reports and maps.
Census blocks are grouped into block groups, which are grouped into census tracts. There are on average about 39 blocks per block group. Blocks typically have a four-digit number; the first number indicates which block group the block is in. For example, census block 3019 would be in block group 3.