题目内容
计算,怎样简便怎样算
![]() ![]() ![]() ![]() | ![]() ![]() ![]() | (![]() ![]() |
58×![]() ![]() | 67×![]() | ![]() ![]() ![]() |
解:(1)
×
+
×
,
=
×(
+
),
=
×1,
=
;
(2)
×
×
=
;
(3)(
-
)×88,
=
×88-
×88,
=40-11,
=29;
(4)58×
+12÷2
,
=58×
+12×
,
=(58+12)×
,
=70×
,
=30;
(5)67×
,
=(66+1)×
,
=62+
,
=62
;
(6)
÷(3-
-
)
=
÷[3-(
+
)],
=
÷[3-1],
=
÷2,
=
.
分析:(1)(3)运用乘法分配律简算;
(2)约分计算;
(4)把除法改为乘法,运用乘法分配律简算;
(5)根据数字特点,把67看作66+1,运用乘法分配律简算;
(6)括号内运用减法的性质简算,最后算括号外的除法.
点评:考查了分数的四则混合运算,注意审题,灵活运用所学的运算定律进行简便计算.




=



=

=

(2)




(3)(


=


=40-11,
=29;
(4)58×


=58×


=(58+12)×

=70×

=30;
(5)67×

=(66+1)×

=62+

=62

(6)



=



=

=

=

分析:(1)(3)运用乘法分配律简算;
(2)约分计算;
(4)把除法改为乘法,运用乘法分配律简算;
(5)根据数字特点,把67看作66+1,运用乘法分配律简算;
(6)括号内运用减法的性质简算,最后算括号外的除法.
点评:考查了分数的四则混合运算,注意审题,灵活运用所学的运算定律进行简便计算.

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