题目内容
| 8.15-2.93-1.07-3.15 |
解:
(1)
÷[
],
=
÷[
÷
],
=
÷
,
=
;
(2)
÷23+
×
,
=
×
+
×
,
=(
+
)×
,
=1×
,
=
;
(3)
×5.7+5.9×7.5-1.6×
,
=7.5×5.7+5.9×7.5-1.6×7.5,
=7.5×(5.7+5.9-1.6),
=7.5×10,
=75;
(4)8.15-2.93-1.07-3.15,
=(8.15-3.15)-(2.93+1.07),
=5-4,
=1.
分析:(1)先算小括号里面的加法,再算中括号里面的除法,最后算中括号外面的除法;
(2)根据乘法分配律进行计算;
(3)根据乘法分配律进行计算;
(4)根据加法交换律及减法的性质进行计算.
点评:四则混合运算,先弄清运算顺序,然后再进一步计算,能简算的要简算.
(1)
=
=
=
(2)
=
=(
=1×
=
(3)
=7.5×5.7+5.9×7.5-1.6×7.5,
=7.5×(5.7+5.9-1.6),
=7.5×10,
=75;
(4)8.15-2.93-1.07-3.15,
=(8.15-3.15)-(2.93+1.07),
=5-4,
=1.
分析:(1)先算小括号里面的加法,再算中括号里面的除法,最后算中括号外面的除法;
(2)根据乘法分配律进行计算;
(3)根据乘法分配律进行计算;
(4)根据加法交换律及减法的性质进行计算.
点评:四则混合运算,先弄清运算顺序,然后再进一步计算,能简算的要简算.
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