1、1巧用运算定律进行小数乘除法的简便计算一、仔细审题,填一填。(每空1分,共19分)1根据运算定律填空。(1)2.50.99()2.5(2)(12.51.2)0.4(3)0.51.250.20.8(4)0.75(39.3)52找规律写得数。60.95.46.66.945.546.6666.9445.5546666666.9 6.66666666.9二、下面的计算对吗?对的画“”,错的画“”并改正。(每小题4分,共16分)167.812.50.867.8(12.50.8)67.8106.78()2.0.81.2540.250.81.2540.25112()34.40.2540.250.410.40
2、.4()4.6.40.83.60.2(6.43.6)(0.80.2)10110()三、下面各题,怎样简便就怎样算。(每小题3分,共30分)5.790.991.010.86862.8152.8 19.80.59.828.5753.575 5.461015.462.83.50.4 14.70.358.60.454.50.14 0.550.60.117四、聪明的你,答一答。(共35分)1双十一快到了,网上各店都打折销售,乐乐网购了菠萝和火龙果各3.5千克,乐乐一共花了多少钱?(6分)22019年军运会在湖北武汉举行,盈盈兄妹俩和父母坐车去看开幕式,往返的交通费要多少元?(7分)3一个没拧紧的水龙头每
3、小时大约浪费水0.58千克,解放小学昨天有6个水龙头没拧紧,一天会浪费多少千克水?(7分)4一间活动室宽4.8米,长是宽的1.25倍,里面有24个同学在练习书法,平均每个同学占地多少平方米?(7分)5导游王阿姨一共要买30瓶矿泉水。请你算一算,哪家超市便宜?一共需要多少元?(8分)答案一、1.(1)10.01(2)12.50.41.20.4(3)1.250.80.50.2(4)539.30.724445.555444445.55554二、1.改正:67.812.50.85.4240.84.33922改正:0.81.2540.25(0.81.25)(40.25)1113改正:4.40.25(40
4、.4)0.2540.250.40.2510.11.14改正:6.40.83.60.281826三、5.790.995.79(10.01)5.7915.790.015.790.05795.73211.010.86(10.01)0.8610.860.010.860.860.00860.8686862.8152.8(8615)2.81012.8(1001)2.81002.812.82802.8282.8 19.80.59.8219.829.82(19.89.8)2102208.5753.575(8.573.57)5551 5.461015.465.46(1011)5.461005462.83.50.
5、42.8(3.50.4)2.81.42 8.60.454.50.148.60.450.451.4(8.61.4)0.45100.454.50.550.60.1170.11(50.6)0.1170.1130.1170.11(37)0.11101.1四、1.(8.212.8)3.573.5(元)答:乐乐一共花了73.5元。242.5242.522127.5(元)12752255(元)答:往返的交通费要255元。30.5862483.52(千克)答:一天会浪费83.52千克水。44.81.256(米)64.828.8(平方米)288241.2(平方米)答:平均每个同学占地1.2平方米。5A超市:30246(瓶)1569(元)93443(元)B超市:303243(瓶)31.64.8(元)364.840.8(元)4340.8答:B超市便宜,一共需要40.8元。7