1、第1招 巧算小数乘法 学习第1单元后使用QD 五年级上册107.816计算：7.8161.451.697.8163.142.184。经典例题 规范解答：7.8161.451.697.8163.142.1847.8161.451.697.8163.14(107.816)3.14107.8161.451.697.8163.147.816()31.47.816(1.451.693.14)31.47.816(3.143.14)31.4123提示：点击进入题组训练巧用乘法分配律巧用乘法结合律巧用“转化法”进行简算812.50.812.50.0812.5 1计算。100101 111 巧用乘法分配律技 巧
2、 1 8.8812.5 0.9910.1 6.5934.565.56.59 6.59(34.565.5)6.59100 659 0.99100.990.1 9.90.099 9.999 3.26993.26 73.410173.4 73.4(1011)73.4100 7340 3.26(991)3.26100 326 44.42.5 402.542.50.42.5 100101 111(12.50.8)(40.25)10110(0.42.5)(81.25)2 1102206.42.51.252计算。巧用乘法结合律技 巧 2 12.53.20.252.54.4 0.1259.628096.2(0
3、.1258)(9.6210)96.2 196.296.202.541.1 101.11111.15411.146 11.1(5446)11.11001110巧用“转化法”进行简算技 巧 3 3计算。66.6922.22311.1 6 9 11.1 2 23()()1.256.171.251.83 1.25(6.171.83)1.258101.256.170.12518.31.256.171.25 0.1 18.3()10010.110099.90.110.1199.9 100(10.199.9)1.0199.9100110100.9111000100.9110899.0999.910.199.
4、9993.20.453.20.423.20.13 3.2(0.450.420.13)3.21 3.2 3.20.450.324.20.032133.2 0.45 3.2 0.1 4.2 3.2 0.01 13()()3.847.60.76100.161.6 3.847.67.66.167.6(3.846.16)7.610763.847.60.7661.65.57.73.35.55.51 5.5(7.73.31)5.510 55 5.57.7330.555.53.336663.333333.331 3.33(6663331)3.331000 3330 9.992223.333333.333.33 3 222 3.333333.331()(0.81.25)1.134 11.134 4.52 0.8(2.31.17)1.25(3.270.73)0.81.131.254
