9+11= 14+8= 27-7= 7+5= 15-5=
15-( )=6 5+( )=13 ( )-8=7
11-( )=3 ( )-8=4 12-( )=7
①14.56﹣6.62+5.44﹣8.38
②×0.8×12.5
③5.9×63+59×3.7
④÷[×(﹣)]