解题思路:(1)运用加法结合律以及减法性质解答,
(2)(3)依据四则运算计算方法,先算第二级运算,再算第一级运算,如果只含有同一级运算,按照从左到右顺序计算,有括号先算括号里面的解答.
(4)(6)运用乘法分配律解答,
(5)化3.2=8×0.4,再运用乘法结合律解答.
(1)23.8−
7
9+6.2−
11
9],
=(23.8+6.2)-([7/9]+[11/9]),
=30-2,
=28;
(2)37.5+12.5÷2.5×4,
=37.5+5×4,
=37.5+20,
=57.5;
(3)(
7
9+
2
3×
5
6)÷
4
15,
=([7/9]+[5/9])÷
4
15,
=[4/3]÷
4
15,
=5;
(4)(
5
17+
4
13)×13×17,
=[5/17]×13×17+[4/13]×13×17,
=65+68,
=133;
(5)125×3.2×25,
=(125×8)×(0.4×25),
=1000×10,
=10000;
(6)777×[7/100+444×0.09+333×0.05,
=111×(7×
7
100]+4×0.09+3×0.05),
=111×(0.49+0.36+0.15),
=111×1,
=111.
点评:
本题考点: 整数、分数、小数、百分数四则混合运算;运算定律与简便运算.
考点点评: 考查了运算定律与简便运算,四则混合运算.注意运算顺序和运算法则,灵活运用所学的运算律简便计算.