问题
解答题
用简便方法计算
|
答案
(1)3
1 |
4 |
3 |
5 |
1 |
4 |
=3
1 |
4 |
1 |
4 |
=(3
1 |
4 |
1 |
4 |
=1×4.6,
=4.6;
(2)9.5×3.8+6
1 |
5 |
1 |
2 |
=9.5×3.8+6.2×9.5,
=9.5×(3.8+6.2),
=9.5×10,
=95;
(3)14×72+42×76,
=14×(3×24)+42×76,
=(14×3)×24+42×76,
=42×24+42×76,
=42×(24+76),
=42×100,
=4200;
(4)
4 |
19 |
=
4 |
19 |
=
4 |
19 |
4 |
19 |
=5+
16 |
19 |
=5
16 |
19 |