9.99x1.01的简便运算

严超灵47021.01x9.9 - 9.9的 简便计算计算 -
孙步武15872633652 ______ 1.01*9.9-9.9=1.01*9.9-1*9.9=(1.01-1)*9.9=0.099

严超灵47020.99x0.9的简便算法 -
孙步武15872633652 ______ 9.99*0.9 =0.99*(1-0.1) =0.99*1-0.99*0.1 =0.99-0.099 =0.891

严超灵470289.9x9.9+99x1.01用简便方法 -
孙步武15872633652 ______ 89.9x9.9+99x1.01 =8.99x99+99x1.01 =99x(8.99+1.01) =99x10 =990

严超灵470289.9x9.9+99x1.01简便方法 -
孙步武15872633652 ______ 89.9x9.9+99x1.01=89.9x9.9+9.9x10.1=9.9*(89.9+10.1)=9.9*100=990

严超灵47029.99乘8.5 - 1.01乘7.6的简便计算 -
孙步武15872633652 ______ 9.99x8.5-1.01x7.6=(10-0.01)x8.5-(1+0.01)x7.6=10x8.5-0.01x8.5-7.6-0.01x7.6=85-0.085-7.6-0.076=84.915-7.6-0.076=77.315-0.076=77.239

严超灵47021.01x0.99的简算,怎么做? -
孙步武15872633652 ______ 1.01*0.99 = (1+0.01)*(1-0.01) = 1*1 - 0.01 * 0.01 = 1- 0.0001 = 0.9999, 数学里的平方差公式(a+b)(a-b)=a²-b²

严超灵47021.01乘9.9减9.9怎样简便 -
孙步武15872633652 ______ =(1.01-1)*9.9 =0.01*9.9 =0.099

严超灵47029.99x10.01递等式计算 -
孙步武15872633652 ______ 9.99*10.01 =9.99*10+9.99*0.01 =99.9+0.0999 =99.9999

严超灵47029点8*1点01的简便方法 -
孙步武15872633652 ______ 9.8x1.01 =9.8x(1+0.01) =9.8x1+9.8x0.01 =9.8+0.098 =9.898

严超灵47029.99x9.99十999简便 -
孙步武15872633652 ______ 9.99x9.99十999 =(10-0.01)x(10-0.01)+999 =100-2x10x0.01+0.0001+999 =100-0.2+0.0001+999 =99.8+0.0001+1000-1 =99.8001-1+1000 =98.8001+1000 =1098.8001