下列各题能简算的要简算. 3.1+2.4+1.9+3.6 300-288÷24 48×(3/8+5/6) 0.46×98+0.92 4/5×2/5÷4/5×2/5 21÷(1/3+2/5)÷9/11.
问题描述:
下列各题能简算的要简算.
3.1+2.4+1.9+3.6 | 300-288÷24 | 48×(
|
0.46×98+0.92 | ||||||||||||
|
21÷(
|
答
(1)3.1+2.4+1.9+3.6,
=(3.1+1.9)+(2.4+3.6),
=5+6,
=11;
(2)300-288÷24,
=300-12,
=288;
(3)48×(
+3 8
),5 6
=48×
+48×3 8
,5 6
=18+40,
=58;
(4)0.46×98+0.92,
=0.46×(100-2)+0.92,
=0.46×100-0.46×2+0.92,
=46-0.92+0.92,
=46;
(5)
×4 5
÷2 5
×4 5
,2 5
=(
÷4 5
)×(4 5
×2 5
),2 5
=1×0.16,
=0.16;
(6)21÷(
+1 3
)÷2 5
,9 11
=21÷
÷11 15
,9 11
=21÷(
×11 15
),9 11
=21÷
,3 5
=35.