This is a fun collection of on-line quizzes:
The mostly math quizzes cover topics from arithmetic, exponents, and place value to trigonometry and calculus. There are also some science, geography, and vocabulary quizzes as well.
The quizzes are fairly elementary, but they are easy to get into. And fun!
While at the 2011 Bridges Conference, I learned a bit about the mathematics of weaving. One of our projects was to plan and weave a tiling of the plane. For some unknown reason, I chose a Halloween theme.
I was out in the neighborhood shopping for seafood and stopped by the local fishmonger. I inspected the jumbo shrimp, which were going for $17.99 a pound. I decided I’d take a pound, and placed my order.
The fishmonger threw a handful of shrimp on the scale. The pile weighed in 0.85 pounds, so he added a few more. The additional shrimp took the total over a pound, so he took one off. Slowly, this series of shrimp was converging to the appropriate limit.
Still a little over, the fishmonger exchanged two large shrimp with two smaller ones. This brought the total weight down to 0.95 pounds.
I turned my attention to the rest of my grocery list. It wasn’t until after I had cashed out and left the store that it hit me: The fishmonger had charged me $17.99 for the shrimp! That is, he charged me for a full pound, even though I only received 0.95 pounds.
Now, a 5% margin of error might not seem too bad, but because of the high cost of shrimp, that 5% error amounts to 90 cents! With all the attention paid to that weighing, I feel like he could have been a bit more accurate. I would also hypothesize that the vast majority of weighing inaccuracies are of the “under” variety.
My inattentiveness here cost me a dollar, but at least I walked away with something to think about. And while the fishmonger may have won a dollar, he lost all my future business.
Through Math for America, I am part of an on-going collaboration with the New York Times Learning Network. My latest contribution, a Test Yourself quiz-question, can be found here:
https://learning.blogs.nytimes.com/2011/09/07/test-yourself-math-sept-7-2011/
This question comes from an article about the proliferation of expensive summer camps catering to wealthy clientele. How much does a day of high-end summer camp cost?
This is a terrific collection of Math Research projects designed to engage middle school, high school, and undergraduate students in independent mathematical research:
http://www.york.cuny.edu/~wu/jm/
The projects cover topics like graph coloring, triangulation, nets, and voting matrices. Each project contains background information, examples, a fundamental problem, and extensions.
Although many of the questions (and answers) may be known, the projects mostly explore areas of mathematics that are not as well-traveled as Number Theory or Euclidean Geometry. Students who engage with this material may very well find themselves looking at something new, or in a new way.