① ÷ × = | ② ÷( + )= | ③ × + ÷5= |
④1- ÷ = | ⑤ - ÷ - = | ⑥( + )÷ = |
÷
×
=
×
×
=
;②
÷(
+
)=


=
×
=
;③
×

=
×

=
×(
)=
×1=
;④1-


=1-
×
=1-

=
;⑤
-
÷
-
=
-
×
-
=
-

=
-(
+
)=
-1=
;⑥(
+
)÷
=(
+
)×
=
×
×
=
+1=
.分析:除③、⑥两题把除改为乘后,利用乘法分配律进行简便计算,⑤题做完除法可利用连续减去两个数等于减去两个数的和简算外,其余题目运用四则混合运算的顺序解答即可.
点评:在四则混合运算中,抓住题目的特点,适当利用运算定律使计算简便.
÷5=