Explain how to read a 6-digit grid coordinate on a standard topographic map.

• A. Six-digit coordinates specify easting and northing to the nearest 10 meters.
• B. Six-digit coordinates specify easting and northing to the nearest 100 meters; read the first digit pairs as 100-meter squares within the 1,000-meter grid; combine digits to form full coordinate.
• C. Six-digit coordinates specify easting and northing to the nearest 1,000 meters.
• D. Six-digit coordinates are read as two three-digit numbers representing grid zones.

Answer: (B)

Six-digit grid references give you location to the nearest 100 meters by refining a 1,000-meter (1 km) grid square on the map. You split the six digits into two groups of three: the first three digits show how far east within the 1-km square, and the last three show how far north within the same square. Each digit in those groups represents a 100-meter step, so together they pin the exact 100-meter block inside that 1-km box. To read the full position, locate the 1-km square on the map, read the 100-meter offsets from the two groups, and combine them with the square’s location to get the easting and northing to 100-meter accuracy.