The default scientific number format included in Microsoft Excel is as follows:
0.00E+00
This format shows one number before the decimal point and two
numbers after. If you create a custom scientific number format that has
more than one place indicator before the decimal point, the numbers before
the decimal point may not appear as you would expect.
For example, the following table shows a number, how the number is
displayed in Microsoft Excel with the 0.00E+00 format code, how the
number is displayed with the 00.00E+00 format code, and how you
might expect it to be displayed with the 00.00E+00 format code.
0.00E+00 00.00E+00 00.00E+00
Number Actual Actual Expected
-------------------------------------------------------
0.00000245 2.45E-06 02.45E-06 24.5E-07
Versions of Microsoft Excel earlier than Microsoft Excel version 5.0 display the number as shown in the "Expected" column. Depending on the number in the cell and the number of significant digits before the decimal point in the custom format code, Microsoft Excel 2000 may or may not show the number as expected.