怎样算简便就怎样算. ①3/7−(1/2−3/7) +1/2 ②73÷0.8÷12.5 ③1/2×201−1/2 ④(1/3+1/8−1/24)÷ 1/24.
问题描述:
怎样算简便就怎样算. ①
|
②73÷0.8÷12.5 | ③
|
④(
|
答
①
−(3 7
−1 2
) +3 7
1 2
=
-3 7
+1 2
+3 7
,1 2
=(
+3 7
)+(3 7
−1 2
),1 2
=
+0,6 7
=
;6 7
②73÷0.8÷12.5,
=73÷(0.8×12.5),
=73÷10,
=7.3;
③
×201−1 2
1 2
=(201-1)×
,1 2
=200×
,1 2
=100;
④(
+1 3
−1 8
)÷ 1 24
1 24
=(
+1 3
-1 8
)×24,1 24
=
×24+1 3
×24-1 8
×24,1 24
=8+3-1,
=10.