能用简便方法计算的用简便方法计算．18.5-3.21-4.794.5×0.7+5.5×0.70.4×（2.5+0.25）14.2×9.9+1.42．

Question

能用简便方法计算的用简便方法计算．
18.5-3.21-4.79
4.5×0.7+5.5×0.7
0.4×（2.5+0.25）
14.2×9.9+1.42．

Answer 1

①18.5-3.21-4.79
=18.5-（3.21+4.79）
=18.5-8
=10.5；

②4.5×0.7+5.5×0.7
=（4.5+5.5）×0.7
=10×0.7
=7；

③0.4×（2.5+0.25）
=0.4×2.5+0.4×0.25
=1+0.1
=1.1；

④14.2×9.9+1.42
=1.42×99+1.42
=1.42×（99+1）
=1.42×100
=142．