题目内容
6.5-(1.6÷5-0.3) | 7.2-2.7÷15-0.32 | ||||||||||||
|
|
分析:(1)先算括号内的除法,再算括号内的减法,最后算括号外的减法;
(2)先算除法,原式变为7.2-0.18-0.32,运用减法的性质简算;
(3)把除法变为乘法,运用乘法分配律简算;
(4)先算小括号内的,再算中括号内的,最后算括号外的.
(2)先算除法,原式变为7.2-0.18-0.32,运用减法的性质简算;
(3)把除法变为乘法,运用乘法分配律简算;
(4)先算小括号内的,再算中括号内的,最后算括号外的.
解答:解:(1)6.5-(1.6÷5-0.3)
=6.5-(0.32-0.3)
=6.5-0.02
=6.48;
(2)7.2-2.7÷15-0.32
=7.2-0.18-0.32
=7.2-(0.18+0.32)
=7.2-0.5
=6.7;
(3)
×31-1÷
=
×31-1×
=
×(31-1)
=
×30
=
;
(4)
÷[
×(
-
)]
=
÷[
×
]
=
÷
=
×
=2.
=6.5-(0.32-0.3)
=6.5-0.02
=6.48;
(2)7.2-2.7÷15-0.32
=7.2-0.18-0.32
=7.2-(0.18+0.32)
=7.2-0.5
=6.7;
(3)
3 |
8 |
8 |
3 |
=
3 |
8 |
3 |
8 |
=
3 |
8 |
=
3 |
8 |
=
45 |
4 |
(4)
9 |
10 |
1 |
2 |
6 |
5 |
3 |
10 |
=
9 |
10 |
1 |
2 |
9 |
10 |
=
9 |
10 |
9 |
20 |
=
9 |
10 |
20 |
9 |
=2.
点评:考查了运算定律与简便运算,四则混合运算.注意运算顺序和运算法则,灵活运用所学的运算定律简便计算.
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