脱式计算(能简便的用简便方法) 28.8-640%-2.8-4.6 7/8×370%+5.3×0.875+7/8 86×75%+14÷4/3 9/32÷[75%-(7/16-25%)] (7/12-37.5%)×24-5/9.
问题描述:
脱式计算(能简便的用简便方法)
28.8-640%-2.8-4.6
×370%+5.3×0.875+7 8
7 8
86×75%+14÷
4 3
÷[75%-(9 32
-25%)]7 16
(
-37.5%)×24-7 12
. 5 9
答
(1)28.8-640%-2.8-4.6
=28.8-6.4-2.8-4.6
=28.8-2.8-(6.4+4.6)
=26-11
=15;
(2)
×370%+5.3×0.875+7 8
7 8
=0.875×3.7+5.3×0.875+0.875
=(3.7+5.3+1)×0.875
=10×0.875
=8.75;
(3)86×75%+14÷
4 3
=86×75%+14×75%
=(86+14)×75%
=100×75%
=75;
(4)
÷[75%-(9 32
-25%)]7 16
=
÷[75%-9 32
]3 16
=
÷9 32
9 16
=
;1 2
(5)(
-37.5%)×24-7 12
.5 9
=(
-7 12
)×24-3 8
.5 9
=
×24-7 12
×24-3 8
5 9
=14-9-
5 9
=4
.4 9