既然是简便方法,楼上两位从32.4看出是18*1.8,有点难了点
32.4-12.4*1.8=32.4-12.4*（2-0.2）=32.4-12.4*2+12.4*0.2
=32.4-24.8+2.48
=（32.4+2.48）-24.8
=34.88-24.8=10.08