【題目】計算下面各題,能簡算的要簡算.
(+
﹣
)×72 1.5×[0.02÷(2.1﹣2.09)]
÷[1﹣(
+
)]
6.5×2.4+6.5×4.6+0.3×65 (7.8﹣2.4)÷×
÷[(
﹣
)÷
]
【答案】(1)(+
﹣
)×72
=×72+
×72﹣
×72
=32+60﹣18
=92﹣18
=74;
(2)1.5×[0.02÷(2.1﹣2.09)]
=1.5×[0.02÷0.01]
=1.5×2
=3;
(3)÷[1﹣(
+
)]
=÷[1﹣
]
=÷
=;
(4)6.5×2.4+6.5×4.6+0.3×65
=6.5×2.4+6.5×4.6+3×6.5
=6.5×(2.4+4.6+3)
=6.5×10
=65;
(5)(7.8﹣2.4)÷×
=5.4÷×
=27×
=;
(6)÷[(
﹣
)÷
]
=÷[
÷
]
=÷
=.
【解析】
試題分析:(1)、(4)根據乘法分配律進行簡算;
(2)先算小括號里面的減法,再算中括號里面的除法,最后算乘法;
(3)再算中括號里面的減法,最后算除法;
(5)先算小括號里面的減法,再算除法,最后算乘法;
(6)先算小括號里面的減法,再算中括號里面的除法,最后算括號外面的除法.
解:(1)(+
﹣
)×72
=×72+
×72﹣
×72
=32+60﹣18
=92﹣18
=74;
(2)1.5×[0.02÷(2.1﹣2.09)]
=1.5×[0.02÷0.01]
=1.5×2
=3;
(3)÷[1﹣(
+
)]
=÷[1﹣
]
=÷
=;
(4)6.5×2.4+6.5×4.6+0.3×65
=6.5×2.4+6.5×4.6+3×6.5
=6.5×(2.4+4.6+3)
=6.5×10
=65;
(5)(7.8﹣2.4)÷×
=5.4÷×
=27×
=;
(6)÷[(
﹣
)÷
]
=÷[
÷
]
=÷
=.
科目:小學數學 來源: 題型:
【題目】用0、0、6、9組成不同的四位數,其中最大的數是(_________),最小的數是(________),不讀出零的數可能是(______),讀出零的數可能是(______)。
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