题目内容
| 脱式计算(能简算的要简算) (1)1 375+450÷18×25 | (2) | (3)9.08×101 |
| (4)1.21×42-(4.46+0.14) | (5) | (6) |
解:(1)1375+450÷18×25,
=1375+25×25,
=1375+625,
=2000;
(2)
,
=
+
×
,
=
+
,
=
;
(3)9.08×101
=9.08×(100+1),
=9.08×100+9.08,
=908+9.08,
=917.08;
(4)1.21×42-(4.46+0.14)
=50.82-4.6,
=46.22;
(5)
×
+
=
×
+
×
,
=
×
×2,
=
;
(6)
=
×(
-
),
=
×0,
=0.
分析:算式(1)(2)(4)(5)根据四则混合运算的运算顺序计算即可:先算乘除,再算加减,有括号的要先算括号里面的;
算式(3)可将101拆分为100+1后再根据乘法分配律计算;
算式(5)可根据乘法分配律进行计算.
点评:在完成有关于分数的四则混合运算题目时要细心,注意通分约分.
=1375+25×25,
=1375+625,
=2000;
(2)
=
=
=
(3)9.08×101
=9.08×(100+1),
=9.08×100+9.08,
=908+9.08,
=917.08;
(4)1.21×42-(4.46+0.14)
=50.82-4.6,
=46.22;
(5)
=
=
=
(6)
=
=
=0.
分析:算式(1)(2)(4)(5)根据四则混合运算的运算顺序计算即可:先算乘除,再算加减,有括号的要先算括号里面的;
算式(3)可将101拆分为100+1后再根据乘法分配律计算;
算式(5)可根据乘法分配律进行计算.
点评:在完成有关于分数的四则混合运算题目时要细心,注意通分约分.
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