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1、小数加减法的应用,洋泾菊园实验学校 吴 洁,小胖带了25.2元，他买了一盆8.8元的小盆栽和一卷4.2元的彩带，还剩多少钱？,25.2(8.84.2),25.28.84.2,25.24.28.8,小胖带了25.2元，他买了一盆8.8元的小盆栽和一卷4.2元的彩带，还剩多少钱？,25.2(8.84.2),25.28.84.2,25.24.28.8,=25.213 =12.2,=16.44.2 =12.2,=218.8 =12.2,25.28.84.2 =25.2(8.84.2) =25.213 =12.2,小胖带了25.2元，他买了一盆8.8元的小盆栽和一卷4.2元的彩带，还剩多少钱？,25.2
2、(8.84.2),25.28.84.2,25.24.28.8,=25.213 =12.2,=16.44.2 =12.2,=218.8 =12.2,=,=,abc = a(bc),小胖带了25.2元，他买了一盆8.8元的小盆栽和一卷4.2元的彩带，还剩多少钱？,25.2(8.84.2),25.28.84.2,25.24.28.8,=25.213 =12.2,=16.44.2 =12.2,=218.8 =12.2,25.28.84.2 =25.2(8.84.2) =25.213 =12.2,=,=,abc = a(bc),加 法 运 算 定 律,ab = ba,abc = a(bc),(14.15
3、+5.87)+5.85=14.15+ +5.87 28.937.465.54 =28.93( ) 65.17(19.35+15.17)= 19.35 23.02+ +0.98+6.24= ( 0.98 )+(13.76 ),在里填上合适的运算符号， 内填上适当的数。,+,+,5.85,7.46,5.54,65.17,15.17,+,-,-,23.02,13.76,6.24,(2)17.26+12.48+10.37+22.74,(4) 10.750.4+9.86,计算下面各题，能简便就简便计算。,(1) 10.75+(0.4+0.25),(3) 20.89(4.56+13.89),(2)17.2
4、6+12.48+10.37+22.74,(4) 10.750.4+9.86 =10.35+9.86 =20.21,计算下面各题，能简便就简便计算。,(1) 10.75+(0.4+0.25) =10.75+0.25+0.4 =11+0.4 =11.4,(3) 20.89(4.56+13.89) =20.8913.894.56 =74.56 =2.44,=17.26+22.74+12.48+10.37,=40+12.48+10.37,=52.48+10.37,=62.85,12.480.63 + 1.37 =12.48(0.63+1.37) =12.482 =10.48,21.32(6.32+8.3) =21.326.32+8.3 =15+8.3 =23.3,12.480.63 +1.37 =11.85+1.37 =13.22,21.32(6.32+8.3) =21.326.328.3 =158.3 =6.7,12.480.631.37,辨 析 改 错,我是金牌采购员,用50元买4样商品，总价不能超出50元，但要最接近50元，你准备怎么买？, 8.27元, 5.11元, 9.86元, 11.04元, 6.96元, 24.89元, 19.83元, 12.14元,8.27+ 24.89+ 9.86+ 6.96=,49.98,今天你有什么收获？,谢 谢,