A better approach is a easily verifiable rule:

I've seen a bunch of approaches but the one that always come to mind first is: cents always match dollar amount of total including tax+tip.

So if your bill is $50, and you leave a $10 tip, $60.60 is the total. Then on your credit card statement anything food related is always $xx.xx or $yy.yy. If > $100, then the last two digits of the dollar amount.

If they change the dollar or cent amounts, you'll know.