Hermione wrote:
my problem is when I calculate: 10e100 - 1 the answer is 10e100, the
problem is with the degree of precision, and I don't know how to resolve this

Hello Hermione,

You can do that with the xlpSUBTRACT function in my Excel add-in,
xlPrecision 2.0. For example:

=xlpSUBTRACT("10E+100",1)

This returns the correct answer, which is 100 nines:

99999999999999999999999999999999999999999999999999 99999999999999999999999999999999999999999999999999

You can download the free edition of xlPrecision here, and use it as
long as you wish:

http://PrecisionCalc.com


Good Luck,

Greg Lovern
http://PrecisionCalc.com
Get Your Numbers Right