Alan Frieze and Danny Sleator, professors from Carnegie Mellon's School of Computer Science, are the hosts of this website of puzzles. Every few weeks, they post a new puzzle and a few weeks later, they post the solution and related references. The fairly advanced puzzles generally involve constructing an algorithm or a proof, and some also involve writing a computer program to solve them....

The world is faced with a number of pressing issues, including climate change, food security, and a range of public health epidemics, just to name a few. In an effort to inspire solutions, the Innovation Management site allows a wide range of creative thinkers, scientists, and policy experts to exchange ideas via their Open Innovation Marketplace. Currently, the site has over 14000 persons signed...

As the site's title implies, this site is simply about making graphs. It introduces students to four main types of graphs -- bar, line, pie, and area -- and allows visitors to construct their own. By selecting a line graph, for example, visitors are asked to provide the title of the graph, the titles of the X and Y axes, and then to list the coordinates for all of the points on either axis. With a...

This website is an excellent resource for math teachers teaching any age and level of students. The National Council of Teachers of Mathematics (NCTM), "support[s] teachers to ensure equitable mathematics learning of the highest quality for all students through vision, leadership, professional development and research." Visitors interested in making math fun will certainly want to read the lead...

Many students arriving at college may find that they have forgotten some of the basic skills required to learn various mathematical concepts. Some educational researchers and mathematicians of note have commented that learning math is more than a bit like learning a new language. Keeping that in mind, this site provided by the mathematics department at St. Louis University may be useful for both...

For people of a certain age, the phrase "math worksheet" may conjure images of pieces of paper with wet purple ink, freshly mimeographed. For others, they might just say: "What's a mimeograph?" Both groups will find things to like about this website, which brings together a number of math worksheets for general use. The site is maintained by Scott Bryce, and while some of the materials require a...