756+758+761+764+770 1975+1980+1998+1985+1994怎么简便？谢谢！

Question

如题所述

Answer 1

756+758+761+764+770
=760-4+760-2+760+1+760+4+760+10
=5×760+9
=3800+9
=3809
1975+1980+1998+1985+1994
=1990-15+1990-10+1990+8+1990-5+1990+4
=5×1990-18
=5×(2000-10)-18
=10000-50-18
=9932本回答被提问者采纳