## OCMC Guest Lecture 2 | Professor Po-Shen Loh

**by Cindy Vu, Beckman High School Class of 2017**

On December 7, 2014, students from all over Orange County assembled at Vanguard University to attend a presentation by renowned Carnegie Mellon University math professor, Po-Shen Loh. Students from every level, high school students, passionate middle school students, as well as highly advanced elementary school students were enthralled by his lesson. At this event, OCMC conducted a book signing for “The Original Collection of Math Contest Problems”, written by our very volunteers. With a foreword by Professor Loh, this book explains a plethora of examples, problems, and solutions for mathematicians in search of strategies essential to excelling in math competitions.

Professor Loh, a national lead coach of the USA International Math Olympiad team and MOP instructor since 2002, presented an interactive lesson on one of the most mystifying subjects in mathematics – probability. Notorious apparent-paradox problems were discussed. Using the classic “ball in the bag” example, Professor Loh also elaborated on the other factors of probability. Examples with batting average and the role of size in probability were explained as well as probability fundamentals and inequalities. However, his brilliant lecture on guessing correctly awed the audience. Two eager volunteers from the crowd made their way up to the front of the auditorium. One of the volunteers, Shivana, was asked to write two numbers between 0 and 1. The other volunteer, Evelyn, had to guess which number was greater, the one on the right or left. With this interactive introduction, Professor Loh dove into probability strategies and paradoxes. Members from the audiences challenged Professor Loh to the game of guessing whether the right or left number was greater. Astonishingly, Professor Loh guessed correctly over half of the time. The audience, baffled, attentively watched as Professor Loh explained his strategy. He captivated the spectators in his engaging lecture.

One of the audience members, fifth grader Keith, remarked “Yes, I think it was a very interesting presentation, and I especially liked the probability with x thing since I didn’t know about it before and it was cool.”

Ninth grader John commented, “The presentation was very engaging. Professor Loh is a brilliant mathematician! I liked the way he introduced proofs into his lessons!”

After the presentation, I asked Professor Loh when he realized math was his calling.

Professor Po-Shen Loh replied: “I think I’ve actually always liked it. I wouldn’t call it math. I think actually math was even a bad name, it makes people think about numbers, calculations, intervals. Math is more about thinking – about analyzing. I’ve always really liked analytical thinking, like reasoning and creatively finding solutions to objective questions where you know when you’re done whether you’re right or wrong, since you can prove it or check it. That’s something I guess I was always interested in, and maybe it’s because I didn’t know how to evaluate myself on subjective things, and I just enjoyed the fact that when doing something objective I know when I’m not right, and I can learn from that.”

It was truly a great honor to have Professor Loh come speak on behalf of OCMC. Many students were inspired by the captivating and brilliant mathematician. It was a great opportunity for students to learn more about the perplexing yet fascinating realms of math.