①(
+
+
)×12 ②18.93-6
-3
③163×
-0.75×62-75% ④7
÷
+1
×2
.解:①(
+
+
)×12,=
×12+
×12+
×12,=4+3+2,
=9;
②18.93-6
-3
,=18.93-(6
+3
),=18.93-10,
=8.93;
③163×
-0.75×62-75%,=163×0.75-0.75×62-0.75,
=(163-62-1)×0.75,
=100×0.75,
=75;
④7
÷
+1
×2
,=7
×
+
×2
,=(7
+2
)×
,=10×
,=
.分析:①根据数字特点,运用乘法分配律的逆运算简算;
②运用减法的性质简算;
③把分数、百分数化为小数,运用乘法分配律的逆运算简算;
④把除法改为乘法,运用乘法分配律的逆运算简算.
点评:此题主要考查了四则混合运算的简算,应根据数字特点,运用恰当的运算定律和性质进行简算.