Author: Daily Challenge with Po-Shen Loh

MATHCOUNTS is the largest tournament-style middle school math competition in the United States. In addition to bringing math enthusiasts together, it also provides an opportunity to learn how to think creatively about math by trying challenging questions. To introduce the type of math in this activity, we shared a free MATHCOUNTS mock test as an online mini-course. It simulates a Chapter Sprint Round, with complete solutions provided: https://daily.poshenloh.com/courses/2020-mathcounts-mock

This video explanation is for one of the more difficult combinatorics problems there, and shows how cleverly you can count! It is pulled out from that free online mini-course for coaches, teachers, or parents to preview. Interested students should take the mini-course instead of watching this video, because it is better to try the problem in the context of the mock test first, before seeing the explanation.

The Daily Challenge with Po-Shen Loh (https://daily.poshenloh.com) is a fun and systematic tour of middle school competition math, designed for students who already understand math at school, but are newcomers to extracurricular math. Through an original teaching style that develops creative thinking, students discover the rich world of math that they can build from their foundation. This online course series supports the development of the social initiative expii.com. .

Video source Youtube