Of course. Give the numbers a randomly generated id, and check for the winning value server side. You'd also want display the numbers in a way where it's tougher to compare them than checking the text values--the target value is $('#left h1').text().trim(). So that means using images (not named 1.jpg!) or canvas or something like that.
Also, your app is vulnerable to replay. I can keep POSTing the same request over and over and my score increases.
