Here's one way.

Select your cells then go to Data/Validation, next select "custom" from the
"Allow" menu and in the formula box type:

=LEN(A1)=10
with A1 being the first cell in your selection and the cells formatted as text

HTH
Jean-Guy

"CF" wrote:

How can I format a cell so that ONLY ten numbers can be entered; no less than
ten, and no more than ten can be entered. Also, some of these ten digit
numbers begin with a zero and I would like that zero to display as well as
count as one of the ten digits.

Thanks in advance for your help!