1.借助实物或操作,助学生形成表象在五年级教学长方体、正方体时,我让学生再次拿来长方体的实物(如牙膏盒、化妆品盒等),进行观察,包括正面看、上面看、左面看,观察完后让他们描述自己看到的样子,同位互相说。接下来让他们把这些盒子沿着棱剪开,怎么剪都行,剪完后再拼。反复这样,剪了拼、拼了剪,让学生在这些操作中获得最直接的表象和经验。在六年级学习圆柱、圆锥时也是这样,先让学生观察实物,再根据实物的样子做圆柱圆锥形状的物体。这一阶段千万不要心急,不要认为这些做法没有用,其实这样做正是 1. With the aid of physical or operational help students to form appearances In the fifth grade teaching cuboids, cubes, I let the students once again brought the cuboid in kind (such as toothpaste boxes, cosmetic boxes, etc.) for observation, including the front view, the above look, the left Look, after watching them let them describe what they see, with each other said. Then let them cut these boxes along the edge of the cut, how to cut it all, cut and then spell. Repeatedly, cut the fight, spell the cut, so that students in these operations to obtain the most direct representation and experience. In the sixth grade learning cylinder, cone, too, let the students observe the real thing, and then according to the physical appearance of cylindrical conical objects. Do not be impatient at this stage, do not think these practices are not useful, in fact, this is exactly what