38.8*8.1+513*0.19+11*3.25该如何做

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38.8*8.1+513*0.19+11*3.25该如何做
38.8*8.1+513*0.19+11*3.25该如何做

38.8*8.1+513*0.19+11*3.25该如何做
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)+22
=388+22+1.25×30
=410+37.5
=447.5

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。

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

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

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

用计算机