问题
解答题
脱式计算能简算得要简算. ①1.8÷0.75+9.6÷2.4 ②6.7+
③19×(
④
|
答案
(1)1.8÷0.75+9.6÷2.4,
=2.4+4,
=6.4;
(2)6.7+
+7 8
+2.3,9 8
=(6.7+2.3)+(
+7 8
),9 8
=9+2,
=11;
(3)19×(
+1 3
)×6,7 19
=19×
×6+19×1 3
×6,7 19
=38+42,
=80;
(4)
×5 7
+3×15 4
+5 7
×5 12
,3 7
=
×(5 7
+3+15 4
),3 12
=
×7,5 7
=5.