Expii.com is a free interactive website focused on math and science, where students, teachers, tutors, and enthusiasts are encouraged to add their voices and teaching styles to the canon of problem-solving lessons hosted on the site. Each topic on Expii is built to support multiple explanations to help learners build deep knowledge by connecting with others who offer explanations that make sense to them. The multiple-explanation feature not only allows and adapts to several different learning preferences but also encourages students to add their own voice to the discussion. The Expii Solve section of the site poses thought-provoking, interactive mathematics problems that relate to current events and pop culture. Students can select from a wide range of theme-related math sets, such as Oscars, March Madness, Pi Day, and Climate Change. Each set has five problems that vary in difficulty. Students can get instant feedback while they’re working on their solutions. If they need help, students can follow the links to tutorials at the bottom of the page. After solving a problem, students can see others’ solutions and share their own. Expii was founded by Po-Shen Loh, a mathematics professor at Carnegie Mellon University and national coach of the US International Math Olympiad team.
Each year the American Computer Science League (ACSL) organizes a computer science or programming competition for precollege students in five divisions—Senior, Intermediate, Junior, Classroom, and Elementary. A preliminary competition, in which individual students compete to get their school team qualified for the All-Star Contest, consists of four contests, each of which has two parts: a written section (called “shorts”) and a programming section.
Professor Ian Stewart is students’ guide through Incredible Numbers, an iPad app from Touch Press. Interactive examples—from simple equations to a working Enigma machine—put the concepts behind mathematics at students’ fingertips.