Sine of the Times https://validator.w3.org/feed/docs/rss2.html The Dog Leash Investigation Collaborating on an Extension to a Little-Known Theorem Cartesian and Polar Graphs Introducing Dynagraphs Algebra Cross Number Puzzles Cross Number Puzzles Exploring Multiples on a Dynamic Number Grid Adding and Subtracting on a Dynamic Number Chart Learn to Multiply Like No Bunny’s Business A Quartet of Ellipse Constructions Innovative Approaches to Computer-Based Assessment, Part Three A Double Dissection from The New York Times Dilation Games: Assessment That’s Fun Some Triangle Shearing Investigations Catching the Vibe Constructing Rectangles with Constant Perimeter and Constant Area Protect the Sheep Revisiting the Hundred Chart Exploring a Perimeter-Area Relationship The Folded Circle Construction A Plethora of Hyperbola Constructions Injecting Surprise Into the Triangle Midline Theorem A Triple Number Line Model for Visualizing Solutions to Equations Virtual Cuisenaire Rods Dynagraphs of Linear Functions A Hidden Polygons Puzzle The Return of the Odometer Exploring Triangle Area with Custom-Built Tools Constructing an Ellipse with Web Sketchpad Tools Putting the Power of a Point Theorem to Work Pythagoras Plugged In Make Your Own Fractions The Varied Paths to Constructing a Square Digging Deep Into Varignon’s Theorem Deducing the “Mystery” Fraction A Geometry Gem from Twitter Interactive Array Explorations The Scaled Maps Problem A Dynamic Approach to Finding Pirate Treasure Circle Tracer Challenges Dividing and Subdividing The Expanding Circle Construction Tweaking the Expanding Circle Construction Constructing the Pi-Petal Rose Visual Models for Adding and Subtracting Fractions Pirate Treasure Awaits Arranging Addends Puzzles Revisited Race to the Burning Tent The Cowgirl Problem A Compendium of Elementary Web Sketchpad Activities