| 762-408÷4×5 | 35× + ×14 | 1.5×[0.02÷(2.1-2.09)] |
| 12.5×8.8 | 87.58-(7.58+3.8) | ( + )×4+ . |
=762-102×5,
=762-510,
=252;
(2)35×
+
×14,=10+10,
=20;
(3)1.5×[0.02÷(2.1-2.09)],
=1.5×[0.02÷0.01],
=1.5×2,
=3;
(4)12.5×8.8,
=12.5×(8+0.8),
=12.5×8+12.5×0.8,
=100+10,
=110;
(5)87.58-(7.58+3.8),
=87.58-7.58-3.8,
=80-3.8,
=76.2;
(6)(
+
)×4+
,=
×4+
×4+
,=
+
+
,=
+(
+
),═
+1,=1
.分析:(1)先算除法,再算乘法,最后算减法,
(2)先同时求出两个乘法算式的积,再算加法,
(3)先算小括号里的减法,再算中括号里的除法,最后算括号外的乘法,
(4)把8.8化成8+0.8,运用乘法分配律进行简算,
(5)先去括号,再从左向右进行计算即可,
(6)先运用乘法的分配律进行简算,
点评:考查了整数、分数四则混合运算的顺序,注意灵活运用运算定律进行简算.