| 计算下面各题,能用简便方法算的就用简便方法算. (1)450+450÷18 | (2)(0.64÷16+1.06)÷22 |
(3)![]() | (4)![]() |
=450+25,
=475;
(2)(0.64÷16+1.06)÷22,
=(0.04+1.06)÷22,
=1.1÷22,
=0.05;
(3)
÷[
×(
+
)],=
÷[
×
],=
÷
,=
×
,=
;(4)
×
+
×25%+1÷4,=
×0.25+
×0.25+0.25,=0.25×(
+
+1),=0.25×2,
=0.5.
分析:(1)先算出,再算加;
(2)先算小括号里的除,再算加,最后算括号外面的除;
(3)按四则运算的顺序计算;
(4)把
,25%,1÷4,都看成0.25,利用乘法的分配律计算简便.点评:考查了运算定律与简便运算,四则混合运算.注意运算顺序和运算法则,灵活运用所学的运算律简便计算.

