用简便算发法计998+1246+9989
问题描述:
用简便算发法计998+1246+9989
答
998+1246+9989=(1000-2)+(1250-4)+(10000-11)=1000+1250+10000-2-4-11=12250-17=12233
用简便算发法计998+1246+9989
998+1246+9989=(1000-2)+(1250-4)+(10000-11)=1000+1250+10000-2-4-11=12250-17=12233