（20＋9.744÷2.4）×0.4 5×3.2×25 0.64×25×7.8+2.2 2÷2.5+2.5÷2 194－64.8÷1.8×0.9 36.72÷4.25×9.9 5180－705×6 24÷2.4－2.5×0.8(25%-695%-12%)*3633.02－（148.4－90.85）÷2.5*��ʲô��˼�˺�