A series of educational multi-layered jigsaw puzzles based on the K-12 school curriculum in which puzzles progress in difficulty and pieces have liquid freeform cut lines, cut along the outlines or silhouette of the image, with puzzle pieces getting progressively smaller from top to bottom creating a tiered basin when all pieces are removed, where some layers are interchangeable and some are double-sided. In mathematical puzzles, the change of state from single to double digits is illustrated with a change of object, where the double-digit object is one that would consist of multiple instances of the single-digit object in real life, such as grapes and bunches, and pieces are non-geometrical, non-polygonal, non-spherical and purposefully difficult to distinguish by shape alone.

System and method for additional amusement, entertaining and surprising visual or audible reward provided upon completing the reconstructing of a two-dimensional or three-dimensional jigsaw puzzle. The puzzle pieces include conductive pads connected by a conductor such as a wire, a metallic strip or a conductive paint, so that upon assembling the puzzle, the pads are in contact to form a continuous conductive path. The frame or the puzzle pieces include a battery (or an AC adapter) and a visual or audible signaling device operating upon sensing the continuity of the conductive path. Each of the puzzle pieces may include three or more conductive pads, allowing for the forming of two or more isolated or connected distinct conductive paths. The conductive path can further affect a time measurement and its related display for timing the puzzle solving.