131+132+133+134+135+136+137+138的简便算法
问题描述:
131+132+133+134+135+136+137+138的简便算法
答
原式= 130+1 +130+2+130+3+130+4+130+5+130+6+130+7+130+8
= 130*8 +1+2+3+4+5+6+7+8
=1076