教学片断教师揭示课题“通分”,并对分数基本性质、求最小公倍数的方法及比较分子或分母相同分数的大小,作了复习性练习。继而,由比较分数大小导出例1:“比较3/4和5/6的大小。”师3/4和5/6的分子、分母都不相同,不容易直接比较它们的大小。但我们可根据分数的基本性质,先 Teaching instructors revealed the subject “pass points”, and the basic nature of the score, the method of finding the least common multiple and the numerator or denominator of the same fractional size, made a review exercise. Then, compare the fractional sizes to derive Example 1: “Compare the size of 3/4 and 5/6.” The numerators 3/4 and 5/6 have different denominators and are not easy to compare directly to their size. But according to the basic nature of the scores, first