38.8*8.1+513*0.19+11*3.25该如何做

原式=38.8x（8+0.1）+513x(0.2-0.01)+(10+1)x3.25
=310.4+3.88+102.6-5.13+32.5+3.25
=314.28+97.47+35.75
=447.5

用计算机

38.8*8.1+513*0.19+11*3.25
=388（1-0.19）+513*0.19+1.1*32.5
=388+0.19（513-338）+1.1*32.5
=388+175*0.19+32.5+3.25
=388+35.75+175(0.2-0.01)
=387

凑整法：8，1等于8加0，1， 0，19等于20减1再处以一百，11等于10加1。

38.8×8.1+513×0.19+11×3.25=388×0.81+（388+125）×0.19+11×3.25=388×0.81+388×0.19+125×0.19+11×3.25=388×（0.81+0.19）+1.25×19+11×（1.25+2）=388×1+1.25×19+11×1.25+11×2=388+1.25×（19+11）+2...

38.8×8.1+513×0.19+11×3.25
=388×0.81＋513×0.19＋11×3.25
=（388＋513）×（0.81＋0.19）＋11×3.25
=901＋35.75
=936.75