脱式计算,能简算的简算. 4.2-1.38+5.8-3.62 1/6÷[1÷(3/5-3/10)] 2÷2/3-2/3÷2 3/5×99+3/5.
问题描述:
脱式计算,能简算的简算.
4.2-1.38+5.8-3.62 |
|
2÷
|
|
答
(1)4.2-1.38+5.8-3.62
=(4.2+5.8)-(1.38+3.62),
=10-5,
=5;
(2)
÷[1÷(1 6
-3 5
)]3 10
=
÷[1÷1 6
],3 10
=
÷1 6
,10 3
=
;1 20
(3)2÷
-2 3
÷2 2 3
=3-
,1 3
=2
.2 3
(4)
×99+3 5
3 5
=(99+1)×
,3 5
=100×
,3 5
=60.