(1)加法结合律 3.29+0.73+2.27 =3.29+(0.73+2.27) =3.29+3 =6.29 (2)减法的性质 3.29-0.73-2.27 =3.29-(0.73+2.27) =3.29-3 =0.29 (3)减法的性质 7.32-(3.32+2.5) =7.32-3.32-2.5 =4-2.5 =1.5 (4)减法交换律 7.35-3.25-3.35 =7.35-3.35-3.25 =4-3.25 =0.75 (5)同级运算交换 3.29+0.73-2.29+2.27 =(3.29-2.29)+(0.73+2.27) =3.35×(0.25×4) =1+3=4