I just plugged your exact code into a button click subroutine, commented out
the last two lines that show the form, put 1 into B27 and clicked the
button.

The number put into H27 (as shown in the formula bar) is 0.693000018596649
and this is shown in the cell  itself as 0.693.

This was a brand new workbook in Excel 2003. Making column H wider showed
me up to a maximum of 9 decimal  places without changing the format. With
extreme narrowing, I could get it to show fewer decimal places.

Format of the cell is "General". If I change it to "Number", I get two DP,
and then can increase the number of displayed decimal places without
trouble.

So ... no idea what you're trying, but it looks as though your cell is badly
formatted. Change it back to "General" and make it wide enough to see a
reasonable number of decimal places.