(1)(-12)×1
(2)-0.00125×(-
)(3)-(-24)×|-6|
(4)(-4)×(-8)-(-9)×

(5)(-7)×(-0.35)×0
(6)

(7)(-0.4)÷0.02
(8)

(9)(-
)÷(-16)÷(-2)解:(1)(-12)×1=-12;(2)-0.00125×(-
),=0.00125×
,=
×
,=
;(3)-(-24)×|-6|,
=24×6,
=144;
(4)(-4)×(-8)-(-9)×
,=32+6,
=38;
(5)(-7)×(-0.35)×0=0;
(6)(-
+
-
)×(-48),=(-
)×(-48)+
×(-48)+(-
)×(-48),=8-36+4,
=12-36,
=-24;
(7)(-0.4)÷0.02,
=-(0.4÷0.02),
=-20;
(8)(-3
)×(-2
),=
×
,=
;(9)(-
)÷(-16)÷(-2),=(-
)×(-
)×(-
),=-
×
×
,=-
.分析:(1)负数与正数相乘得负数;
(2)把小数化为分数,约分计算,根据同号得正,异号得负,结果应为负数;
(3)先求出-(-24)=24,然后根据负数的绝对值等于正数,则|-6|=6;
(4)先算乘法,两数相乘,同号得正,异号得负,再算减法;
(5)任何数和0相乘都得0;
(6)运用乘法分配律简算,同时注意运算符号;
(7)先确定商的符号,再算0.4÷0.02;
(8)先确定积的符号:负负得正,再算3
×2
;(9)先确定商的符号为负数,把除法改为乘法,进行计算.
点评:此题考查了正负数的乘法和除法,在计算时,应根据乘法和除法法则进行.