Question

用简便方法计算 用简便方法计算 3.45×102 0.47×0.5×0.8 0.46×1.9+0.54×1.9

Answer 1

3.45×102
=3.45×(100+2)
=3.45×100+3.45×2
=345+6.9
=351.9

0.47×0.5×0.8
=0.47×(0.5×0.8)
=0.47×0.4
=0.188

0.46×1.9+0.54×1.9
=(0.46+0.54)×1.9
=1×1.9
=1.9

Answer 2

3.45×102 =3.45x(100+2)=345+3.45x2=351.9
0.47×0.5×0.8=0.47×(0.5×0.8)=0.47×0.4=0.188

0.46×1.9+0.54×1.9=(0.46+0.54)×1.9=1×1.9=1.9

Answer 3

3.45×102 =3.45x(100+2)=345+3.45x2=351.9
0.47×0.5×0.8=0.47×0.4=(0.5-0.03)x0.4=0.5x0.4-0.03x0.4=0.2-0.012=0.188
0.46×1.9+0.54×1.9=(0.46+0.54)×1.9=1x1.9=1.9