动手操作,亲自实践,都是我们提倡的学习方法。但是,推理判断,合理想象,也是必不可少的,有时甚至更需要想象和推理。【问题】一个正方体表面涂满红色,然后如下图切开,切开的小正方体中,六个面都没有涂色的有几个?【思路点睛】沿着上图的办法将这个正方体切开,共可以得到27个小正方体。这27个小正方体中,每个顶点处的那个小正方体3面涂色,因为有8个顶点,所以3面涂色的有8个(见图1)。 Hands-on and hands-on practice are all ways we learn. However, reasoning and judging, reasonable imagination, is also indispensable, sometimes imagining and reasoning are even more necessary. [Question] A cube painted red surface, and then cut as shown below, cut the small cube, the six sides are not painted a few? [Ideas dot eye] along the figure approach to the cube cut , Can get a total of 27 small cubes. Of these 27 small cubes, the small cube at each vertex is 3-sided in color, with 8 vertices on 3 sides (see Figure 1).