Question

大家帮帮忙数学题“1+2+3+4+5+6+5+4+3+2+1/6666×6666”怎样简便计算啊?

Answer 1

=1+2+3+4+5+6+5+4+3+2+1

=2(1+2+3+4+5)+6

=30+6

=36