能简便的用简便方法计算.56-(0.15+920)÷1.899989+9989+989+1369.87-6.25-(29.87+3.75)0.05×[(24+49)×38+49×5823+215+235+263.-数学
1 |
9 |
1 |
9 |
=(999
8 |
9 |
1 |
9 |
8 |
9 |
1 |
9 |
8 |
9 |
1 |
9 |
=1000+100+10,
=1110;
(3)69.87-6.25-(29.87+3.75),
=69.87-6.25-29.87-3.75,
=(69.87-29.87)-(6.25+3.75),
=40-10,
=30;
(4)0.05×[ 10.6÷(4.5+
4 |
5 |
=0.05×[10.6÷5.3],
=0.05×2,
=0.1;
(5)(24+
4 |
9 |
3 |
8 |
4 |
9 |
5 |
8 |
=24×
3 |
8 |
4 |
9 |
3 |
8 |
4 |
9 |
5 |
8 |
=9+
4 |
9 |
3 |
8 |
5 |
8 |
=9+
4 |
9 |
=9
4 |
9 |
(6)
2 |
3 |
2 |
15 |
2 |
35 |
2 |
63 |
=
2 |
1×3 |
2 |
3×5 |