| 200-180÷15×2 | 43×99+43 | 46.71-6.81-3.19 |
×15×![]() | ÷( - )×![]() | × + ÷ . |
=200-12×2,
=200-24,
=176;
(2)43×99+43,
=43×(99+1),
=43×100,
=4300;
(3)46.71-6.81-3.19,
=46.71-(6.81+3.19),
=46.71-10,
=36.71;
(4)
×15×
,=9×
,=2;
(5)
÷(
-
)×
,=
÷
×
,=
×
,=
;(6)
×
+
÷
,=
×
+
×
,=
×(
+
),=
×1,=
.分析:(1)先算除法,再算乘法,最后算减法;
(2)运用乘法分配律简算;
(3)根据减法的性质简算;
(4)按照从左到右的顺序计算;
(5)先算小括号里面的减法,再算括号外的除法,最后算括号外的乘法;
(6)先把除法变成乘法,再运用乘法分配律简算.
点评:本题考查了四则混合运算,注意运算顺序和运算法则,灵活运用所学的运算定律进行简便计算.