四年级数学下册课件 小数乘法（北师大版）
文档属性
| 名称 | 四年级数学下册课件 小数乘法（北师大版） |  | |
| 格式 | rar | ||
| 文件大小 | 788.7KB | ||
| 资源类型 | 教案 | ||
| 版本资源 | 北师大版 | ||
| 科目 | 数学 | ||
| 更新时间 | 2010-03-29 19:40:00 | ||
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文档简介
课件17张PPT。北师大版四年级数学下册教学目标本节课我们主要来学习小数乘法，同学们要结合具体的实例理解并掌握小数乘法的计算方法，能够解决相关的实际问题。Oral calculation0.34×2=
0.1×0.2=
0.4×2=2.3×3=
0.6×0.4=
2.1×10=1.4×0.2=
0.5×0.3=
1.1×0.2=0.680.020. 86.90.24210.280.150.2256×73= 4088
5.6 ×73=
5.6×7.3=13×37= 481
1.3×3.7=
1.3×0.37=408.840.884.810.481根据第一个算式的积，写出下面的积．The product has the same
decimals as the two factors.两个因数共有几位小数,
积就有几位小数 .New knowledgeHere is Xiao Ming’s room. What information do you know from the picture?New knowledgeThe length is 3.6 meters The width is 2.8 meters Can you ask some maths questions? What’s the area of this room?3.6 meters2.8 metersNew knowledge3.6×2.8=Who can estimate(估算)?3.6 meters2.8 meters3.6×2.8=×103 6×102 8÷100.New knowledge3.6×2.8=×103 6×102 8÷100.New knowledgeOne decimalOne decimalTwo decimals3.6 meter2.8 meter1.15 meterWhat’s the area of the balcony(阳台)?1.15×2.8=Who Can estimate? New knowledge 1. 1 5
× 2. 8 9 2 0
2 3 03 2 2 0Two decimalsOne decimalThree decimals． New knowledge1、将小数看作整数计算。
2、根据两个因数的小数位数， 在积上点上小数点。总结：How do we calculate decimal multiplication? Can you give the decimal points to the following?.0.0Now ,let’s do exercise.给下面的积点上小数点。Please work out the following products.=1.2=5.76=0.256=0.384=4.9=12.74两个因数中有一个因数小于1，积就小于另一个因数。
两个因数中有一个因数大于1，积就大于另一个因数。在下面的算式中填上“＞”或“＜”。＜＞＞＜已知算式36×122=43.92丢了小数点，
想一想:要使算式成立,
这两个因数的小数点各在什么位置?逆向思维训练：ConclusionWhat did we learn today?
0.1×0.2=
0.4×2=2.3×3=
0.6×0.4=
2.1×10=1.4×0.2=
0.5×0.3=
1.1×0.2=0.680.020. 86.90.24210.280.150.2256×73= 4088
5.6 ×73=
5.6×7.3=13×37= 481
1.3×3.7=
1.3×0.37=408.840.884.810.481根据第一个算式的积，写出下面的积．The product has the same
decimals as the two factors.两个因数共有几位小数,
积就有几位小数 .New knowledgeHere is Xiao Ming’s room. What information do you know from the picture?New knowledgeThe length is 3.6 meters The width is 2.8 meters Can you ask some maths questions? What’s the area of this room?3.6 meters2.8 metersNew knowledge3.6×2.8=Who can estimate(估算)?3.6 meters2.8 meters3.6×2.8=×103 6×102 8÷100.New knowledge3.6×2.8=×103 6×102 8÷100.New knowledgeOne decimalOne decimalTwo decimals3.6 meter2.8 meter1.15 meterWhat’s the area of the balcony(阳台)?1.15×2.8=Who Can estimate? New knowledge 1. 1 5
× 2. 8 9 2 0
2 3 03 2 2 0Two decimalsOne decimalThree decimals． New knowledge1、将小数看作整数计算。
2、根据两个因数的小数位数， 在积上点上小数点。总结：How do we calculate decimal multiplication? Can you give the decimal points to the following?.0.0Now ,let’s do exercise.给下面的积点上小数点。Please work out the following products.=1.2=5.76=0.256=0.384=4.9=12.74两个因数中有一个因数小于1，积就小于另一个因数。
两个因数中有一个因数大于1，积就大于另一个因数。在下面的算式中填上“＞”或“＜”。＜＞＞＜已知算式36×122=43.92丢了小数点，
想一想:要使算式成立,
这两个因数的小数点各在什么位置?逆向思维训练：ConclusionWhat did we learn today?