人教版小学五年级数学上册《练习三》(课堂PPT).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,*,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,*,练习三,人教版小学五年级上册数学,1,（,1,）,1258,12.58,1.258,12.50.8,12.50.08,1.250.08,0.1250.8 1.250.8 125,0.08,1,、口算,:,=,1000,=,10,=,0.1,=,100,=,1,=,1,=,10,=,0.1,（,2,）,254,250.4,250.04,2.54,0.254,0.2540,=,10,=,100,=,10,=,10,=,1,=,1,=,10,2,2,、按要求保留积的小数位数。,保留一位小数：,1.21.4=1.68,0.378.4=3.108,3.143.9=12.246,保留两位小数：,0.861.2=1.032,2.340.15=0.351,1.050.26=0.273,1.7,3.1,1.03,0.35,12.2,0.27,3,2.,一幢大楼有,21,层，每层高,2.84,米。这幢大楼约高多少米？,（得数保留整数。）,2.8421,=59.64,60,（米）,答：这幢大楼约高,60,米。,4,3.,世界上第一台电子计算机很大，它的质,量相当与,6,头,5.85,吨重的大象，这台计,算机有多重？（得数保留整数。）,5.856,=35.04,35,（吨）,答：这台计算机重,35,吨。,5,4,、用简便方法计算下面各题。,4.80.25,0.5,2.33,8,（,0.8+0.04,）,150,=,4,1.2,0.25,=4,0.25,1.2,=1,1.2,=,1.2,=2.33,（,0.5,8,）,=2.33,4,=,9.32,=0.8,150+0.04150,=,120+6,=,126,6,1.22.5+0.82.5,0.3,2.5,0.4,1.5105,=1.5,(,100+5,),=1.5,100+1.5,5,=150,+7.5,=,157.5,=,（,1.2+0.8,）,2.5,=2,2.5,=,5,=0.3,（,2.5,0.4,）,=0.3,1,=0.3,7,（,0.8+0.04,）,150,=0.8,150+0.04150,=120+6,=126,1.01,101-,1.01,=1.01,（,101-1,）,=1.01,100,=101,8,答：买门票一共需要,17.5,元。,=7.5+10,=17.5,（元）,2.53+52,9,每瓶,1.3,元，一共要花多少钱？,1.3,24,6,=31.26,=187.2,（元）,6.,24,6,1.3,=1441.3,=187.2,（元）,答：一共要花,187.2,元。,10,3.760.25,25.8,0.094,25.8,25.894,7.,下面各题计算得对吗？把,不对的改正过来。,50.41.9,1.8,50.40.1,5.04,数学 诊所,数学 诊所,改正：,50.41.9,1.8,95.76-1.8,93.96,改正：,3.760.25,25.8,0.94,25.8,26.74,11,回收,1,吨废纸，可以保护,16,棵树，回,收,54.5,吨废纸可以保护多少棵树？,1654.5=,872,（棵）,答：回收,54.5,吨废纸可以保护,872,棵树。,12,9,、,计算下面各题，你认为怎样简便就怎样计算。,2.028.5,=,（,2+0.02,）,8.5,=2,8.5+0.028.5,=,17+0.17,=,17.17,2.028.5,=,2.02,（,8+0.5,）,=2.02,8+2.020.5,=,16.16+1.01,=,17.17,13,1.25+4.6+0.75,=1.25,+0.75+4.6,=,2+4.6,=,6.6,14,1.67.51.25,=2,0.8,7.5 1.25,=,（,2,7.5,）,（,0.8,1.25,）,=1.5,1,=,1.5,15,561.25,=7,8,1.25,=7,（,8,1.25,）,=7,10,=,70,3.471.5,=3.4,（,7 1.5,）,=3.4,10.5,=3.4,（,10+0.5,）,=3.4,10+3.40.5,=,34+1.7,=,35.7,16,0.80.250.412.5,=,（,0.8,12.5,）,（,0.25 0.4,）,=1,1,=,1,17,10,、学校食堂每周要用掉,1200,双一次性筷子，每双筷子,0.03,元，每周用掉的筷子一共多少钱？,12000.03=36,（元）,答：每周用掉的筷子一共要,36,元钱。,18,24.53031,=735,31,=,22785,（千克）,答：,24.5,公顷松柏林,31,天分泌杀菌素,22785,千克。,19,用多种方法计算。,8881.25,2.54.8,=8,1.25,111,=10,111,=1110,888,1.25,=,（,800+80+8,）,1.25,=1000,1.25+801.25+81.25,=1000+100+10,=1110,20,用多种方法计算。,2.54.8,=2.5,4,1.2,=10,1.2,=12,2.54.8,=2.5,（,4,+0.8,）,=2.5,4+2.50.8,=10+2,=12,21,