Sine of the Times https://validator.w3.org/feed/docs/rss2.html Teaching with Web Sketchpad A Trio of Parabola Constructions Exploring Conic Sections with Sketchpad A Quartet of Ellipse Constructions Constructing an Ellipse with Web Sketchpad Tools A Plethora of Hyperbola Constructions The Swimming Pool Problem A Compendium of Elementary Web Sketchpad Activities Pattern Block Puzzles Building with Pattern Blocks Adding and Subtracting on an Open Number Line Protect the Sheep Drawing an Ellipse with Pins and String Drawing Ellipses with a Congruent Triangle Construction A Beautiful Application of Shearing Catching the Vibe About Experiments with a Color Calculator Transformation Dances Exploring a Perimeter-Area Relationship A Sliding Rulers Approach to Adding and Subtracting Introducing the Elipso A Ping-Pong Puzzle From a Sketchpad Editor The Mysteries of Polygon Flats Drawing Conic Sections Point by Point What’s the Appropriate Role for the Teacher when using Computer Games? Discovery by Dragging Understand the Sine Function by Dancing It Multiplication Arrays Binomial Multiplication and Factoring Games Adding and Subtracting Integers The Scaled Maps Problem Dividing and Subdividing Race to the Burning Tent The Interior Angle Sum: An Embodied Investigation Introducing Web Sketchpad at the 2021 NCTM Annual Meeting A Paper Folding Investigation from Connected Geometry Exploring Scaled Polygons Euclid Walks the Plank The Art of Parametric Equations Hats Off to This Aperiodic Tiling Adventures of the Scooting Tick Mark Zooming in on Place Value Constructing Rectangles with Constant Perimeter and Constant Area The Origami-Math Connection Construct a Building: Modeling Multiplication with Arrays Generalizing the Pythagorean Theorem Introducing Dynagraphs Dilation Games: Assessment That’s Fun A Pythagorean Tree Grows in Your Web Browser