脱式计算,能简算的简算.
4.2-1.38+5.8-3.62??????????
?0.125×0.25×32
2÷-÷2?????????????
?90.5×99+90.5.
网友回答
解:(1)4.2-1.38+5.8-3.62???
=4.2+5.8-(1.38+3.62)
=10-5
=5;
(2)0.125×0.25×32
=0.125×0.25×8×4
=(0.125×8)×(0.25×4)
=1;
(3)2÷-÷2??
=2×-×
=3-
=2;
(4)90.5×99+90.5
=90.5×(99+1)
=90.5×100
=9050;
故