题目内容
简便计算
| 43×99+43 | ||
| 3.5×98+35×0.2 | 250× |
解:(1)43×99+43,
=43×(99+1),
=43×100,
=4300;
(2)
-
+
-
,
=(
+
)-(
+
),
=1-1,
=0;
(3)
×
-
÷13,
=
×
-
×
,
=(
-
)×
,
=
×
,
=
;
(4)3.5×98+35×0.2,
=3.5×98+3.5×2,
=3.5×(98+2),
=3.5×100,
=350;
(5)250×
+250×
,
=250×(
+
),
=250×1,
=250;
(6)
×12.5×
×8,
=(
×
)×(12.5×8),
=
×100,
=330.
分析:(1)根据乘法分配律进行简算;
(2)根据加法交换律和结合律进行简算;
(3)根据乘法分配律进行简算;
(4)根据乘法分配律进行简算;
(5)根据乘法分配律进行简算;
(6)根据乘法交换律和结合律进行简算.
点评:根据题意,找准所运用的运算定律,然后再进一步简算即可.
=43×(99+1),
=43×100,
=4300;
(2)
=(
=1-1,
=0;
(3)
=
=(
=
=
(4)3.5×98+35×0.2,
=3.5×98+3.5×2,
=3.5×(98+2),
=3.5×100,
=350;
(5)250×
=250×(
=250×1,
=250;
(6)
=(
=
=330.
分析:(1)根据乘法分配律进行简算;
(2)根据加法交换律和结合律进行简算;
(3)根据乘法分配律进行简算;
(4)根据乘法分配律进行简算;
(5)根据乘法分配律进行简算;
(6)根据乘法交换律和结合律进行简算.
点评:根据题意,找准所运用的运算定律,然后再进一步简算即可.
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