小学数学五年级上册小数乘法简算口算练习.ppt

4.7199 1258.8=4.7(2001)=1250.811=4.72004.71=10011=940-4.7=1100=935.3 253.2125(20+1)0.63=（250.4）（8125）=200.63+0.63=101000=12.6+0.63=10000=13.23,1040.25 7.2125=(100+4)0.25=9(0.8125)=1000.25+40.25=900=25+1=260.992.54 7.55-(1.36+0.55)=7-1.36=5.64,8.810.2 5.810.1-5.8=8.8(10+0.2)=5.8(10.1-0.1)=8.810+8.80.2=58=88+1.76=89.763.212.5-12.52.4 5.27-3.99=12.5(3.2-2.4)=5.27-4+0.1=12.50.8=1.37=1,672-3.6-6.4 848-269-131-48=672-(3.6+6.4)=848-48-269-131=672-10=800-(269+131)=662=800-400=4004.863+635.1+6.3 9.9+99.9+999.9=(4.8+5.1+0.1)63=10+100+1000-0.3=1063=1110-0.3=630=1109.7,4.7199 1258.8 253.2125(20+1)0.63,1040.25 7.2125 0.992.54 7.55-(1.36+0.55),8.810.2 5.810.1-5.8 3.212.5-12.52.4 5.27-3.99,672-3.6-6.4 848-269-131-484.863+635.1+6.3 9.9+99.9+999.9,