Merry Mathematics, Ho Ho Ho!
Math is not bound to anything, at least not for this guy, and his students. They are stuck with it even during Christmas. Fortunately, this guy had a blessing from Santa and has the perfect gift for all his students.
Source: mandatory.com
So, he dressed in a Santa cap, presented them with the ultimate equation of Christmas. Don’t know how or where he learned this equation with the answer, merry = X-mas, but he sure nailed it. No way, his students are not paying attention to him now.