This week’s "Article of the Week” by Estelle Basor,

(professor emeritus of mathematics at the California Polytechnic State University (Cal Poly), and deputy director of the American Institute of Mathematics), details this past summer’s online program studying dynamics and data pertaining to the COVID-19 pandemic. Sponsored by AIM and NSF (The National Science Foundation), this program was attended by over 40 graduate students and advanced undergraduates chosen from over 550 applicants.

The students developed mathematical models exploring topics from the interaction of COVID-19 with the environment, to the role of social justice factors such as health insurance access, to the impact of human behavioral interventions on the spread of the disease. Learn more about their findings, impacts, and results in this week’s “Article of the Week.”

The goal remains to get three in a row, but the rule and number of pieces varies… This week’s activity, “Achi” is a new twist on the classic tic-tac-toe game! Presented as an online math “mind stretcher” last June by the AIMC (The Alliance of Indigenous Math Circles), this 2-person game is originally from the Ashanti people of Ghana in West Africa. Begin with a 3 by 3 diagram of horizontal and vertical lines and 4 tokens per player. Take turns placing a token on one of the nine possible points where two or more lines intersect. But think! Can a player always get 3 tokens in a row along one of the straight lines? Are there strategies to ensure you always win? Is there a way to play that guarantees nobody loses? What if players only begin with 3 tokens? What if you change the look of the game board? With these and other scenarios, the game of Achi is sure to challenge your views about ordinary tic-tac-toe!