9+11= 14+8= 27-7= 7+5= 15-5=
15-( )=6 5+( )=13 ( )-8=7
11-( )=3 ( )-8=4 12-( )=7
( ) ( ) ( ) ( )
47->39 +78<80 89->88-9 50+<48+9
计算:54-8=?
想:先算
再算