## Girls’ Angle Bulletin, Volume 10, Number 5

Volume 10, Number 5 opens with an interview with Ruth Charney, the Theodore and Evelyn Berenson Professor of Mathematics at Brandeis University. Prof. Charney studied geometric group theory and received her doctoral degree in mathematics from Princeton University. She was formerly a professor at Ohio State University.

Next comes the second half of the article by Milena Harned and Miriam Rittenberg on NIM Counting. They give a general formula for the number of ways a NIM game with 2 starting piles can be played out and they investigate the form of the formula.

Errorbusters! returns after a long absence! The column, which was originated by Cammie Smith-Barnes, has been revived by Hamilton College Assistant Professor of Mathematics Courtney Gibbons. In her first installment, she writes about “Errors of Apathy,” which include such dastardly errors as substituting $x^2 + y^2$ for $(x+y)^2$.

The cover is a homage to the 24th cyclotomic polynomial. Of late, Emily and Jasmine have been filling reams of scratch paper with computations involving cyclotomic polynomials as they continue their quest to classify all “nice triangles”. The computation is daunting and they don’t even know if the computation will prove useful in their quest, but they bravely press on! Such is math research…

Next up: This summer’s batch of Summer Fun problem sets. This year, we have problem sets on cyclotomic polynomials (as a kind of primer to Emily and Jasmine’s work), sets (by Debbie Seidell), the fourth dimension, and unsuspected appearances of geometry (by Matthew de Courcy-Ireland).

We conclude with a few problems from our traditional end-of-session math collaboration and a few chocolate Hasse diagrams from the mini-chocolate tasting of Meet 11.

We hope you enjoy it!

Finally, a reminder: when you subscribe to the Girls’ Angle Bulletin, you’re not just getting a subscription to a magazine. You are also gaining access to the Girls’ Angle mentors.  We urge all subscribers and members to write us with your math questions or anything else in the Bulletin or having to do with mathematics in general. We will respond. We want you to get active and do mathematics. Parts of the Bulletin are written to induce you to wonder and respond with more questions. Don’t let those questions fade away and become forgotten. Send them to us!

We continue to encourage people to subscribe to our print version, so we have removed some content from the electronic version.  Subscriptions are a great way to support Girls’ Angle while getting something concrete back in return.  We hope you subscribe!