强阳转弱一定生男孩么:用简便算发法计998+1246+9989

来源:百度文库 编辑:杭州交通信息网 时间:2024/06/10 06:17:44

998+1246+9989=(1000-2)+(1250-4)+(10000-11)=1000+1250+10000-2-4-11=12250-17=12233

998+(2+1233+11)+9989=(998+2)+1233+(11+9989)

998+1246+9989
=(1000-2)+(10000-11)+1246
=1233