Of the first $$100$$ whole numbers,~\uline{~~~~~~~~~~}~use the digit $$2$$ at least once. 
Overseas Competition->Knowledge Point->Number Theory Modules->Place Value and Number Bases->Numbers
$$2$$, $$12$$, $$20-29$$, $$32$$, $$42$$, $$52$$, $$62$$, $$72$$, $$82$$, and $$92$$ use a $$2$$; that\textquotesingle s $$19$$ numbers. 