一、充分感知,建立清晰的表象如在教学长方体概念时,能通过直观,让学生充分感知各种各样的长方体,使其建立各种长方体的表象,从而形成关于长方体的观念性形象,学生就会获得关于长方体的清晰概念。在教学长方体的概念时,既要出示有利于学生认识六个面的长方体,如文具盒、火柴盒、药箱等,又要出示有利于认识12条棱的长方体,如铅丝焊接成 First, full perception, the establishment of a clear appearance, such as the concept of teaching cuboid, through intuitive, so that students fully aware of a wide range of cuboids, to create a variety of cuboid appearance, thus forming a conceptual image about the cuboid, the students You get a clear idea about the cuboid. In teaching the concept of cuboid, it is necessary to produce a rectangular parallelepiped that is conducive to students' understanding of six sides, such as stationery boxes, matchboxes, medicine boxes, etc., and also to produce rectangular parallelepipeds that can be used to recognize 12 bars,