Some maps have lines that make squares, like a checkerboard. This is called a grid. It helps us say exactly where something is.
Key idea
On a grid map, every square has a name: a letter from the top and a number from the side, like B4.
Worked example: Name the colored square
What is the name of the colored square?
- Go straight up from the square to the top edge. The letter is B.
- Go straight across to the side edge. The number is 4.
- Letter first, then number.
Answer: B4.
Why it works
One letter and one number are enough to point to one square, and only one. It is quicker than saying "the third row, near the middle, kind of on the left."
Common mistake
Children read the number first, or count from the wrong corner. Always say the letter first, and read the letters and numbers printed on the edges instead of counting.
For the grown-up. Play a game of "battleship" on graph paper: hide a sticker in a square and give the square's name.