目前,录音、录像、幻灯、多媒体等电教媒体已广泛运用于自然课堂教学,而实物投影仪的出现又为自然教学开辟了一片新天地。由于实物投影仪能把自然教学中经常出现的标本、模型、文字、图片、实验装置等不经制片,直接投影成像,且图像清晰,色彩逼真,所以备受自然教师的青眯。 一、优化教师讲解 由于实物投影仪具有放大效应,能生动地表现一些微小实物和文字。教师在讲解教学内容时,投影与内容相关的实物、图片或文字,能使讲解更生动形象,清晰具体,从而使学生很快掌握知识要领。如在教学《果实的形成》时,桃花较小,学生观察事物可见度小,效果差。教师利用 At present, audio-visual media such as audio recording, video recording, slideshow and multi-media have been widely used in nature classroom teaching. The emergence of physical projectors has opened up a new world for natural teaching. As the physical projector can naturally appear in the teaching of specimens, models, text, pictures, experimental devices without filming, direct projection imaging, and the image is clear, vivid colors, so much the favor of natural teachers. First, to optimize the teacher to explain As the real projector has a magnifying effect, can vividly display some small objects and text. Teachers explain the teaching content, projection and content-related objects, pictures or text, to explain the more vivid image, clear and specific, so that students quickly master the essentials of knowledge. As in the teaching of “the formation of fruit”, peach smaller, students observe things visibility is small, the effect is poor. Teachers use