解题思路:①②③⑦⑧根据四则混合运算法运算顺序计算即可:先算乘除,再算加减,有括号的要先算括号里面的;
④可根据乘法结合律计算;
⑤⑥可根据乘法分配律计算;
①[3/4]+[1/6]-[3/8]
=[11/12]-[3/8],
=[13/24];
②3.2-0.85-1[4/5]
=2.35-1.8,
=0.55;
③3.2×[5/8]-[2/3]÷2
=2-[1/3],
=1[2/3];
④1.725×4×0.5
=1.725×(4×0.5),
=1.725×2,
=3.5;
⑤([7/8]+[13/16])÷[13/16]
=[7/8]×[16/13]+[13/16]×[16/13],
=[14/13]+1,
=2[1/13];
⑥1.8×0.72+1.28×1.8
=1.8×(0.72+1.28),
=1.8×2,
=3.6;
⑦2÷([1/2]-[1/3])
=2÷[1/6],
=12;
⑧57.6÷[(1.25+25%)×0.32]
=57.6÷[1.5×0.32],
=57.6÷0.48,
=120.
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: 当算式中同时含有中括号与小括号时,要注意先算小括号里面的,再算中括号里面的.