Rectangles asks players to draw rectangles that fill a grid without leftover squares. Each number on the board is an area to match, so a 6 might become a 2-by-3 or a 1-by-6, and the whole puzzle only works when every rectangle fits and every cell is covered.
As learners drag out each rectangle, they practice area as length times width, factor pairs, and spatial planning. They have to try one size, notice when a piece blocks another clue, and adjust, which builds flexible thinking about arrays and how numbers can be arranged as shapes.
PlayMath.org and the Julia Robinson Mathematics Festival have partnered to bring some of the real-world activities from the math festivals to life online. JRMF is a nonprofit that hosts non-competitive math festivals, where K–12 students explore hands-on puzzles together.