| ①15.89-(6.09-4.11) | ②36.8-44.08÷5.8 | ③75×60%+24× +0.6 |
④( + + )×72 | ⑤ ÷[( + )÷ ] | ⑥43× . |
=15.89+4.11-6.09,
=20-6.09,
=13.91;
②36.8-44.08÷5.8,
=36.8-7.6,
=29.2;
③75×60%+24×
+0.6,=(75+24+1)×0.6,
=100×0.6,
=60;
④(
+
+
)×72,=
×72+
×72+
×72,=30+8+27,
=65;
⑤
÷[(
+
)÷
],=
÷[
÷
],=
÷
,=
;⑥43×
,=(42+1)×
,=42×
+
,=31+
,=31
.分析:①先去括号,再根据加法的交换律简便方法计算即可;
②先算除法,再算减法;
③④⑥根据乘法分配律简便计算;
⑤先计算括号里面的,再计算括号外面的除法.
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.