Multiplication is a rectangle of dots. Turn it a quarter turn and not one dot moves — so 4 × 6 and 6 × 4 are the same block and the same answer. When both sides match, the block is a square.
Hide controls gives you a clean stage to screen-record; click the stage to bring them back. 📄 PDF prints the frame you are looking at. The color tracks the digit and the grouping shows the place, so a frame from here matches the printed deck. If you picked your own colors on the Games page, this page uses them.