On Your Mark, Get Set, Multiply — Quanta Magazine

Did you get caught up in the latest viral math problem, 8÷2(2+2)?

The problem here is simply how we interpret the division symbol. Does ÷ mean divide by the one number right after it or by everything after it? This isn’t much of a concern for most mathematicians, as they don’t use this symbol very often. Ask them to solve this problem and they’ll probably just make the whole thing into a multiplication problem: Once you choose to write it as either

8 \times \frac{1}{2} \times (2 + 2) or 8 \times \frac{1}{2(2+2)},

the ambiguity is gone and the answer is clear. As a multiplication question, this isn’t particularly interesting.

But one multiplication question mathematicians do find interesting may surprise you: What is the best way to multiply?

And what is the best way to multiply? The answer may surprise you! Find out by reading my latest column for Quanta Magazine, freely available here.

By MrHonner, ago

09/12/2019 — Happy Permutation Day!

Today we celebrate a Permutation Day! I call days like today permutation days because the digits of the day and the month can be rearranged to form the year.

And not only is it a permutation day, it’s a palindrome day! Thinking of the date as 9/12/19, we can write 91219, which is a palindrome–a number that reads the same backward and forward. Enjoy the day by rearranging something or doing something backwards! Or perhaps even both.

By MrHonner, ago

Barron’s SHSAT Prep Book

I’m excited to announce that the SHSAT Prep Book I co-authored for Barron’s has been published!

This book is designed to prepare middle school students for New York City’s Specialized High School Test (SHSAT). The SHSAT is the sole admissions criterion for entry into New York City’s specialized schools, which include Stuyvesant, Bronx Science, and Brooklyn Tech. The test is free, and every middle school student in the city is eligible to take it.

This new book reflects the recent changes to the content of the SHSAT, which was re-designed to better represent the standard 7th and 8th grade curricula. It includes an overview of all of the math and ELA content covered on the exam, as well as three complete practice tests.

The book was written with co-author Young Kim, and is currently available on Amazon and in Barnes and Noble stores in New York City.

By MrHonner, ago
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