解题思路:(1)按照从左到右的顺序计算;
(2)先算除法,再算减法;
(3)先算减法,再算乘法,最后算加法;
(4)先算乘法,再算减法,最后算加法;
(5)先算小括号里面的加法,再算括号外的乘法;
(6)先同时运算两个小括号里面的加法和减法,再算除法.
(1)72-44+85,
=28+85,
=113;
(2)234-135÷9,
=234-15,
=219;
(3)144+(57-12)×2,
=144+45×2,
=144+90,
=234;
(4)95-15×6+41,
=95-90+41,
=5+41,
=46;
(5)(15+20)×3,
=35×3,
=105;
(6)(75+30)÷(20-5),
=105÷15,
=7.
点评:
本题考点: 整数四则混合运算.
考点点评: 本题关键是理清楚运算的顺序,找出先算什么,再算什么,根据运算的顺序逐步求解即可.