计算下列各题,能简便都尽量简便.(1)(34-18)÷512(2)[1-(35-14)]÷13(3)3.75×4.8+62.5×0.48(4)415÷(47+48)(5)1991+199.1+19.9

题目简介

计算下列各题,能简便都尽量简便.(1)(34-18)÷512(2)[1-(35-14)]÷13(3)3.75×4.8+62.5×0.48(4)415÷(47+48)(5)1991+199.1+19.9

题目详情

计算下列各题,能简便都尽量简便.
(1)(
3
4
-
1
8
5
12

(2)[1-(
3
5
-
1
4
)]÷13
(3)3.75×4.8+62.5×0.48(4)
4
15
÷(
4
7
+
4
8
(5)1991+199.1+19.91+1.991(6)
44
45
×37.
题型:解答题难度:中档来源:不详

答案

(1)(class="stub"3
4
-class="stub"1
8
)÷class="stub"5
12

=(class="stub"3
4
-class="stub"1
8
)×class="stub"12
5

=class="stub"3
4
×class="stub"12
5
-class="stub"1
8
×class="stub"12
5

=class="stub"9
5
-class="stub"3
10

=class="stub"3
2


(2)[1-(class="stub"3
5
-class="stub"1
4
)]÷13

=[1-class="stub"7
20
]÷13,
=class="stub"13
20
÷13,
=class="stub"1
20


(3)3.75×4.8+62.5×0.48,
=3.75×4.8+6.25×4.8,
=(3.75+6.25)×4.8,
=10×4.8,
=48;

(4)class="stub"4
15
÷(class="stub"4
7
+class="stub"4
8
),
=class="stub"4
15
÷class="stub"15
14

=class="stub"56
225


(5)1991+199.1+19.91+1.991,
=(2000-9)+(200-0.9)+(20-0.09)+(2-0.009),
=(2000+200+20+2)-(9+0.9+0.09+0.009),
=2222-9.999,
=2222-(10-0.001),
=2222-10+0.001,
=2212.001;

(6)class="stub"44
45
×37,
=(1-class="stub"1
45
)×37,
=1×37-class="stub"1
45
×37,
=37-class="stub"37
45

=36class="stub"8
45

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