分数乘法简便计算.ppt

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,分数乘法简算练习课,填空,1,2,25 =,1,50,1,2,（,）,7,9,（,+,）,27=+,5,27,应用了（）律,应用了（）律,用简便方法计算,1,8,（,+,）,24,1,12,9,11,6,7,35,6,7,18,-,7,18,4,5,3,7,10,-,3,7,3,5,7,5,7,2,3,1,3,+,39,23,38,下面的计算对吗？请说明理由。,3,7,+,4,7,3,2,3,7,（,+,）,4,7,=,3,2,5,7,5,7,+,13,（,13+1,）,=,5,7,1,5,4,5,5,6,5,6,+,（）,1,5,4,5,5,6,=,基础练习,能力提高,开放练习（,在 中填上合适的数，使计算简便,）,计算下面各题，能简算的要简算。,5,12,（,-,）,36,5,18,7,15,8,9,5,21,（,6,）,-,3,4,4,3,8,9,+,1,9,15,12,13,12,+,12,13,4,7,5,4,2+,拓展,5,6,1,5,37,3,4,3,4,1,5,2,5,+,+0.75,3,5,3,4,-,5,14,13,14,9,11,5,11,+,拓展训练：,