Worksheet data is in one of three forms: numbers, text, or date/time. Thematic maps require data as numbers or date/time. Numeric and date/time data allows MapViewer to perform arithmetic computations necessary to create a thematic map. Text data, even if it contains numeric digits, cannot be used in arithmetic computations and cannot be used to create most thematic maps.
Numbers can consist of digits (0 - 9), decimal points ( . ), the letters "e," "d," "E," or "D" (indicating an exponent), and the plus (+) or minus (-) sign. If you type any characters other than these when entering a number (or type any of the special characters more than once), MapViewer automatically converts the cell entry to text. You can also convert numeric data to text by typing a single quotation mark ( ' ) in front of the number. MapViewer does not display the single quotation in the worksheet cell, however.
By default, numeric, and date/time data is right justified in a cell, and text is left justified. However, cell entries, whether numeric, date/time, or text, can also be justified by specifying the desired alignment using Data | Format | Format Cells | Alignment.