Good points from davido
 
and,
<demi-hemi-semi-joke> does "-10" or "1.2" also qualify? After all, neither the minus nor the decimal point is a "number." </demi-hemi...>

and <serious point>: the OP's exact language definitely countenances any 2-digit number (where "number"'s meaning is roughly eq "value") equal to or less than 10. But it does NOT rule out the possibility that the data may contain three digit numbers, such as "007" nor single-digit numbers, like "4;" negative values such as "-10" (<BTW>Does the sign in a signed decimal count as a "digit' for OP's intended purpose?) or -- for that matter -- (hex) 0x0a (which, last time I checked) is less than 0x10. Indeed the discussion would have quite different parameters had OP used "2 digit numeral" ( ?? which would mean unicode ?!) or "two numeral value" instead of "number."</point>

So, <peroation>^1. gentle readers, perhaps the imprecision in OP's post and the wisdom in some of the replies (notably, that of reasonablekeith, who says he is neither and that cited above) will remind all who visit here, that snippet samples of data and desired outcomes can help those who would help you.

1. Devil's Dictionary