六年制小学数学教材第九册第三单元的内容是三角形、平行四边形和梯形的特征及面积的计算,这些都属几何知识的内容,是小学教学的基础之一。我在教学中综合运用认真观察、动手操作、思路分析的方法,学生能较快地掌握这些几何知识,教学效果较好。 一、动手操作帮助认识几何图形 在教学这一单元时,首先让学 The content of the third unit of the ninth volume of six-year primary school mathematics textbooks is the calculation of the features and areas of triangles, parallelograms and trapeziums, which are the content of the geometric knowledge and are one of the foundations of primary school teaching. I use a combination of careful observation in teaching, hands-on operation, train of thought analysis, students can quickly grasp these geometric knowledge, teaching better. First, hands-on operation to help understand the geometry in the teaching of this unit, first of all to learn