56加99乘99加43(简便)
问题描述:
56加99乘99加43(简便)
答
(56+99)*(43+99)=(55+100)*(42+100)=55*42+55*100+100*42+100*100
=50*42+5*42+5500+4200+10000
=2100+210+19700
=2310+19700
= 22010