Frobel's fourth gift are 8 rectangular parallelepipedons. They compose the same size cube as the second gift's cube and the third gift's one. The third gift was composed of 8 small cubes. The third and fourth gifts are showing us Frobel's educational law that calls partical-whole. This fourth gift's rectangular parallelepipedon has 3 different face, is more complicated than third gift's small cube. Therefore, children are able to manifest more variously one's their own inner creativity. But, the third gift exhibits fortes of facet (surface, angle, edge), against one, the fourth gift exhibits fortes of line (length, width, heigh). To manifest inner creativity by moulding is Frobel's nurturel purpose. As a result of moulding, children take physical world into inner spirit, and cultivate their inner creativity. The 8 rectangular parallelepipedons which follow the 8 small cubes satisfy a creative impulse of child that grown up than before. The fourth gift is plaything for harmony of opposition that internal world and physical world of child. The interactions by mould play (in existance, in knowledge, in beauty) come to children's own mission that man ought to create like God under the law of opposition-harmony.