在日常生活及高年级几何题中,常遇到如何节省包装纸即立体图形的组拼问题:要使拼成的长方体的长、宽、高的长度尽量接近。[结论一]当小长方体长、宽、高是三个不同的素数时,把合数个小长方体的总体积分解质因数,组成三个最接近的数即是大长方体的长、宽、高的长度。[结论二]当小长方体长、宽、高是三个不同的素数(其中必有一个是2)时,把若干个小长方体的总体积分解质因数,组成三个最接近的数即是大长方体的长、宽、高的长度。 In daily life and high school geometry, often encountered how to save wrapping paper that the three-dimensional graphics of the assembly problem: to make the length of the rectangular box, width, height as close as possible. [Conclusions] When the small cuboid length, width, and height are three different prime numbers, the total volumetric dissociation factor of several small cuboids together to form the three closest numbers is the length, width and height of the large cuboid length. [Conclusion 2] When the length, width and height of a small cuboid are three different prime numbers (one of which must be 2), the total volumetric dissociation factor of several small cuboids is composed of the three closest numbers The length, width and height of the cuboid.