计算下列各题:(1)4×0.8×2.5×12.5(2)21-34×12-58(3)89×[34-(716-0.25)](4)495+4995+49995+35.-数学

题目简介

计算下列各题:(1)4×0.8×2.5×12.5(2)21-34×12-58(3)89×[34-(716-0.25)](4)495+4995+49995+35.-数学

题目详情

计算下列各题:
(1)4×0.8×2.5×12.5
(2)21-
3
4
×
1
2
-
5
8

(3)
8
9
×[
3
4
-(
7
16
-0.25)]

(4)
49
5
+
499
5
+
4999
5
+
3
5
题型:解答题难度:中档来源:不详

答案

(1)4×0.8×2.5×12.5
=(4×2.5)×(0.8×12.5),
=10×10,
=100;
(2)21-class="stub"3
4
×class="stub"1
2
-class="stub"5
8

=21-class="stub"3
8
-class="stub"5
8

=21-(class="stub"3
8
+class="stub"5
8
)

=21-1,
=20;
(3)class="stub"8
9
×[class="stub"3
4
-(class="stub"7
16
-0.25)]

=class="stub"8
9
×[class="stub"3
4
-class="stub"7
16
+class="stub"1
4
]

=class="stub"8
9
×class="stub"9
16

=class="stub"1
2

(4)class="stub"49
5
+class="stub"499
5
+class="stub"4999
5
+class="stub"3
5

=class="stub"49+1
5
+class="stub"499+1
5
+class="stub"4999+1
5

=10+100+1000,
=1110.

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