×10÷ × + × ; | × - ÷3; |
18×( +6÷ ); | ÷[ -( - )]. |
① ×10÷ × + ×![]() = × × +![]() = +![]() = +![]() = ![]() =1 ; | |
②18×( +6÷ )=18×( +6× )=18× +18×6×![]() =6+84 =90; |
×
-
÷3=
×(
-1)=
×
=
;④
÷[
-(
-
)]=
÷(
-
+
)=
÷(1-
)=
÷
=
×
=
.分析:分数的四则混合运算规律遵从整数的四则混合运算,先算乘除,后算加减,有括号的,先算括号内的.
点评:此题考查了分数的四则混合运算和分数的简便计算.
×10÷
×
+
;
+6÷
);
×
×
+
+

;
)