2016苏教六级上册分数除以整数.ppt
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Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 1 6 7 20 1 3 9 168 温故而知新 1.抢答。说出下面各数的倒数。 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 2.量杯里有4升果汁,平均分给2个小朋友喝,每人可以喝多少升? 4÷2=2(升) 答:每个小朋友可以喝2升。 温故而知新 把一个数(整数)平均分成几份,求每份是多少,用除法计算。 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 温故而知新 3.量杯里有0.8升果汁,平均分给2个小朋友喝,每人可以喝多少升? 0.8÷2=0.4(升) 答:每个小朋友可以喝到0.4升。 把一个小数平均分成几份,求每份是多少,计算方法和整数一样,用除法计算。 猜一猜:把一个分数平均分几份,用什么方法计算? Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 3、杯里有0.8升果汁,平均分给2个小朋友喝,每人可以喝到多少升? 1 教学新知识 ÷ 2 把一个分数平均分成几份,求每份是多少,计算方法和整数一样,用除法计算。 发现规律 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 量杯里有 升果汁,平均分给2个小朋友喝,每人可以喝多少升? 4 5 4 5 升 ÷ 2= 1 探究学习 先在右图分一分,再算出结果。 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 4 5 升 4 5 升 作业展示 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 2 5 升 4 5 升 2 5 升 1 2 1 2 4 5 升 ÷2= = (升) 4 5 4 5 × 1 2 2 5 ÷2= = (升) 4 5 4 2 5 ? 2 5 把4个 平均分成2份。 1 5 每人喝了 升的 。 4 5 1 2 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. ÷2= 4 5 4 5 × = (升) 1 2 2 5 2 1 4 5 方法一 ÷2= = (升) 方法二 用分数的分子除以整数(0除外) 用分数乘这个整数(0除外)的倒数。 ÷2= 4 5 2 ÷2= 4 5 发现规律 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 如果把 升果汁平均分给3个小朋友喝,每人喝多少升? ÷3= 5 4 3 1 15 4 4 5 答:每人可以喝 升。 4 15 4 5 4 5 ÷3= 4÷3 5 =? Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 分
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