Today, you're in charge of the nation's finances. Some of your options have more short-term savings and some have more long-term savings. When you have closed the budget gaps for both 2015 and 2030, you are done. Make your own plan, then share it online.

"In this article we present a set of unusual dice and a two-player game in which you will always have the advantage. You can even teach your opponent how the game works, yet still win again! Finally, we will describe a new game for three players in which you can potentially beat both opponents - at the same time!"

"Easily incorporate computational thinking into your curriculum with these classroom-ready lessons, examples, and programs"

Journey North is a world-wide project in which K-12 students track wildlife migration and the changing the seasons, share their data with other classrooms, and learn about science, math, and the world around them in the process. "Journey South" (tracking fall's progress in the northern hemisphere) is beginning now, and you can use that program to prepare for spring's Journey North in your classroom. Free registration is required to share data online. The general public is welcome to participate. The site offers standards-aligned lesson plans and resources for teachers, as well as a portal for kids.

"Welcome to the website that is designed to help anyone who is studying Secondary School Mathematics at Level E, Level F, Standard Grades or Higher Still Levels Intermediate 1 or 2 and Higher."

Math teacher and researcher Tom O'Brien offers resources and activities through this site, with planned updates each month to add more materials. These include books published by the UK's Association of Teachers of Mathematics--some out of print --now downloadable and available for purchase. Excerpts from the e-books are available free, as well as three articles by O'Brien and colleagues. O'Brien recommends software as well, some of which is available free of charge.

"The social repository of the world's greatest brain teasers, logical puzzles and mental challenges. Join us to add, rate, and comment on puzzles! "

The Math 2.0 Interest Group is an international network of researchers, educators, families, community leaders and technology enablers. We are collaborating on a variety of research and development projects and conversation threads about social media as it relates to mathematics and mathematics education.

This slide show demonstrates some techniques that would be suitable for an experimental geometry project. The basic shapes of square and circle are explored using open source Geogebra and Dr Geo geometry software. The examples includes exercises in geometric construction, novel solutions and recursive (spiral) constructions. This is mathematics that can be done without algebra. There is some algebra on slide 18, to calculate the radius and area of a semicircle inscribed in a square.

Another fun version

Great exrices for the kids!

These pages demon­strate vi­su­al phe­nom­e­na, and »op­ti­cal« or »vi­su­al il­lu­sions«. The lat­ter is more ap­pro­pri­ate, be­cause most ef­fects have their basis in the vi­su­al path­way, not in the op­tics of the eye.