In his excellent TEDx talk, “Math Class Needs a Makeover”, Dan Meyer affirms some basic truths about math class: 1) anyone can learn to be successful in math, 2) traditional approaches to math instruction have poorly served a large number of our students, and 3) making math instruction practical is the key to making it “stick”.  He never uses the term “UDL” in his talk, but the changes he proposes are all about changing how we represent material, how we express our conclusions, and how we engage with the curriculum – the three principles of Universal Design for Learning.

Here are my ten eleven twelve favorite sites to use to support math instruction.  None of them are procedural guides or electronic worksheets.  They all involve building an environment that the student can manipulate and get immediate feedback on their efforts.  Some of them can be done quickly.  Some take longer.  But, they all make effective use of the “problem-based learning” model.

1. NLVM – http://nlvm.usu.edu
   A vast array of math manipulatives, indexed by grade band and by sub-topic (Number & Operations, Algebra, Geometry, Measurement, and Data Analysis & Probability). This is a long-time favorite of mine.  Most of the applications are built on the Java platform, which unfortunately means they will not work on a Chromebook.  If you have a teacher station with a browser that still runs Java, some of the manipulatives work extremely well with an interactive whiteboard.
2. iSolveIt – http://isolveit.cast.org/home
   CAST provides two iOS apps that keep the goal of developing logic and reasoning skill at the focus, beyond simply providing a right answer.
3. Interactivate – http://www.shodor.org/interactivate/
   Interactivate includes the standard fare of manipulative activities and stock lessons, but goes the extra step of providing ideas and material for Class Discussions.  Also has an associated iOS app.
4. Illuminations – https://illuminations.nctm.org/
   The National Council on Teaching Mathematics provides this set of manipulatives, titled “Illuminations”.  Searchable by grade band and sub-topic.  Includes Common Core and NCTM standards.
5. PhET Interactive Simulations – https://phet.colorado.edu/
   Colorado University provides this set of modern HTML5-based manipulatives.  Math is the basis for some, and is a strong undercurrent for many of the science activities.  Because of the modern platform, these work well on just about any device or screen size.
6. NRich – https://nrich.maths.org/students
   Includes printable support materials for class and teachers.  And, it gives you a chance to explain to the class why the word “maths” shows up all over the place!  Don’t get thrown off by the UK terminology, the activities are indexed for US grade levels as well.
7. SolveMe Math Mobiles – https://solveme.edc.org/
   Without using the words “equation” or “algebra”, this interactive puzzle game provides a great introduction to those concepts, while reinforcing number sense and application of basic operations.
8. Cargo Bridge from Limex Games – http://limexgames.com/games/cargo_bridge/
   The guy has to push the box home.  But, there’s a chasm in the way!  Build a bridge to support the guy and the box, with the limited supplies you have available.  You’ll never hear the question, “When am I ever gonna need to know about triangles in real life?”
9. “Full Steam Ahead” game – http://www.ssgreatbritain.org/full-steam-ahead
   Math abounds in a set of physics and engineering problems based on the real-life advances designed by Isambard Kingdom Brunel.  As you progress through the early tasks, more types of challenges are unlocked.  Build, Test, Tweak, Repeat.
10. Math Playground – http://www.mathplayground.com/math_manipulatives.html
    Somewhat limited set of resources, but the ones that are available are very useful.  Geared more for upper elementary.  Should work well with modern browsers.
11. Desmos Graphing Calculator – https://www.desmos.com/
    A graphing calculator for your browser!  Powerful save, overlay, and editing tools.
12. Geogebra – https://www.geogebra.org/
    Online graphing calculator, and a host of additional tools for math instruction, including geometry, algebra, calculus, statistics, and more.  Downloadable materials as well as online activities.