计算下列各题,能简算的要简算. 89×3/86 7/13÷4+6/13×1/4 1/20+0.24×6.4÷0.32 6-7/8×8/21-1/3.
问题描述:
计算下列各题,能简算的要简算.
89×
3 86
÷4+7 13
×6 13
1 4
+0.24×6.4÷0.32 1 20
6-
×7 8
-8 21
. 1 3
答
(1)89×
3 86
=(86+3)×
,3 86
=86×
+3×3 86
,3 86
=3+
,9 86
=3
;9 86
(2)
÷4+7 13
×6 13
1 4
=
×7 13
++1 4
×6 13
,1 4
=(
+7 13
)×6 13
,1 4
=1×
,1 4
=
;1 4
(3)
+0.24×6.4÷0.321 20
=0.05+0.24×(6.4÷0.32),
=0.05+0.24×20,
=0.05+4.8,
=4.85;
(4)6-
×7 8
-8 21
1 3
=6-
-1 3
,1 3
=5
.1 3