学前准备1

( )×( )×( )×( )×( ) ⒈ 25÷23= ( )×( )×( )

=2( )

=2( )-( )

( )×( )×( ) ×( ) ⒉ a4÷a2= ( )×( )

=a( )

=a( )-( )

(a≠0)