986-297的简便算法是( ) A.986-300-3 B.986-300+3 C.986-200-97
问题描述:
986-297的简便算法是( )
A. 986-300-3
B. 986-300+3
C. 986-200-97
答
986-297,
=986-300+3,
=686+3,
=689;
故选:B.