人教版五年級上冊積的近似數(shù)課件 課件

1、積的近似數(shù),第一單元：小數(shù)乘法,Evaluation only.,ted with Aspose.Slides for .NET 3.5 Client Profile 5.2,Copyright 2019-2019 Aspose Pty Ltd.,1.,計算下面各題。,1.5,24 0.37,2.6 4.02,8.3,一、以舊引新，激活經(jīng)驗,Evaluation only.,ted with Aspose.Slides for .NET 3.5 Client Profile 5.2,Copyright 2019-2019 Aspose Pty Ltd.,2.,求下面各小數(shù)的近似數(shù)。,一、以舊引

2、新，激活經(jīng)驗,（,1,）保留一位小數(shù)。,3.12,3.1,5.549,5.5,0.3814,0.4,（,2,）保留兩位小數(shù)。,4.036,4.04,7.7963,7.80,8.42378,8.42,Evaluation only.,ted with Aspose.Slides for .NET 3.5 Client Profile 5.2,Copyright 2019-2019 Aspose Pty Ltd.,一、以舊引新，激活經(jīng)驗,Evaluation only.,ted with Aspose.Slides for .NET 3.5 Client Profile 5.2,Copyright

3、 2019-2019 Aspose Pty Ltd.,二、創(chuàng)設(shè)情境，自主探究,在實際應(yīng)用中，小數(shù)乘法的積往往不需,要保留很多的小數(shù)位數(shù)，這時可以根據(jù),需要，按“四舍五入”法保留一定的小,數(shù)位數(shù)，求出積的近似數(shù)。,Evaluation only.,ted with Aspose.Slides for .NET 3.5 Client Profile 5.2,Copyright 2019-2019 Aspose Pty Ltd.,（,1,）小狗正在做什么？,（,2,）人們訓(xùn)練小狗緝毒是利用了小狗的什么,特點？,二、創(chuàng)設(shè)情境，自主探究,Evaluation only.,ted with Aspose.

4、Slides for .NET 3.5 Client Profile 5.2,Copyright 2019-2019 Aspose Pty Ltd.,二、創(chuàng)設(shè)情境，自主探究,人的嗅覺細胞約有,0.049,億個，狗的嗅覺細,胞個數(shù)是人的,45,倍。狗約有多少億個嗅覺細,胞？（得數(shù)保留一位小數(shù)。）,Evaluation only.,ted with Aspose.Slides for .NET 3.5 Client Profile 5.2,Copyright 2019-2019 Aspose Pty Ltd.,二、創(chuàng)設(shè)情境，自主探究,人的嗅覺細胞約有,0.049,億個，狗的嗅覺細,胞個數(shù)是人的,4

5、5,倍。狗約有多少億個嗅覺細,胞？（得數(shù)保留一位小數(shù)。）,Evaluation only.,ted with Aspose.Slides for .NET 3.5 Client Profile 5.2,Copyright 2019-2019 Aspose Pty Ltd.,二、創(chuàng)設(shè)情境，自主探究,人的嗅覺細胞約有,0.049,億個，狗的嗅覺細,胞個數(shù)是人的,45,倍。狗約有多少億個嗅覺細,胞？（得數(shù)保留一位小數(shù)。）,Evaluation only.,ted with Aspose.Slides for .NET 3.5 Client Profile 5.2,Copyright 2019-201

6、9 Aspose Pty Ltd.,二、創(chuàng)設(shè)情境，自主探究,人的嗅覺細胞約有,0.049,億個，狗的嗅覺細,胞個數(shù)是人的,45,倍。狗約有多少億個嗅覺細,胞？（得數(shù)保留一位小數(shù)。）,Evaluation only.,ted with Aspose.Slides for .NET 3.5 Client Profile 5.2,Copyright 2019-2019 Aspose Pty Ltd.,二、創(chuàng)設(shè)情境，自主探究,人的嗅覺細胞約有,0.049,億個，狗的嗅覺細,胞個數(shù)是人的,45,倍。狗約有多少億個嗅覺細,胞？（得數(shù)保留一位小數(shù)。）,Evaluation only.,ted with As

7、pose.Slides for .NET 3.5 Client Profile 5.2,Copyright 2019-2019 Aspose Pty Ltd.,二、創(chuàng)設(shè)情境，自主探究,人的嗅覺細胞約有,0.049,億個，狗的嗅覺細,胞個數(shù)是人的,45,倍。狗約有多少億個嗅覺細,胞？（得數(shù)保留一位小數(shù)。）,0.049,45,0.0 4 9,4 5,2 4 5,1 9 6,0,2,.,2 0 5,0,5,舍去,0,和,5,，,保留一位小數(shù)。,2.2,（億個）,Evaluation only.,ted with Aspose.Slides for .NET 3.5 Client Profile 5.

8、2,Copyright 2019-2019 Aspose Pty Ltd.,二、創(chuàng)設(shè)情境，自主探究,人的嗅覺細胞約有,0.049,億個，狗的嗅覺細,胞個數(shù)是人的,45,倍。狗約有多少億個嗅覺細,胞？（得數(shù)保留一位小數(shù)。）,0.049,45,2.2,（億個）,答：狗約有,2.2,億個嗅覺細胞。,0.0 4 9,4 5,2 4 5,1 9 6,0,2,.,2 0 5,Evaluation only.,ted with Aspose.Slides for .NET 3.5 Client Profile 5.2,Copyright 2019-2019 Aspose Pty Ltd.,三、鞏固練習，強化

9、認知,1.,計算下面各題。,0.8,0.9,（得數(shù)保留一位小數(shù)）,1.7,0.45,（得數(shù)保留兩位小數(shù)）,Evaluation only.,ted with Aspose.Slides for .NET 3.5 Client Profile 5.2,Copyright 2019-2019 Aspose Pty Ltd.,三、鞏固練習，強化認知,補充題：,將“,1.35,0.96,”的積用“四舍五入”法保留兩位,小數(shù)，所得的近似數(shù)是（,）。,A.,1.29,B.,1.30,C.,0.13,B,Evaluation only.,ted with Aspose.Slides for .NET 3.5

10、 Client Profile 5.2,Copyright 2019-2019 Aspose Pty Ltd.,三、鞏固練習，強化認知,2.,一種大米的價格是每千克,3.85,元，買,2.5,kg,應(yīng)付,多少錢？,在,實際應(yīng)用,中，應(yīng)該,根據(jù)需要,按,“四舍五入”法保留一定的小數(shù),位數(shù)，求出積的,近似數(shù),。,Evaluation only.,ted with Aspose.Slides for .NET 3.5 Client Profile 5.2,Copyright 2019-2019 Aspose Pty Ltd.,四、全課總結(jié)，暢談收獲,Evaluation only.,ted with Aspose.Slides for .NET 3.5 Client Profile 5.2,Copyright 2019-2019 Aspose Pty Ltd.,五、作業(yè)練習,課堂作業(yè)：,