学前准备1
( )×( )×( )×( )×( ) ⒈ 25÷23= ( )×( )×( )
=2( )
=2( )-( )
( )×( )×( ) ×( ) ⒉ a4÷a2= ( )×( )
=a( )
=a( )-( )
(a≠0)
