16-8= 60+30= 53-6= 70-40= 46-6+40=
59-40= 13-7= 63-8= 84+9= 90-(16+4)=
42+8= 5+77= 100-80= 35+50= 63+20-9=
25+9= 60+21= 76-( )=6 90+( )=99 ( )-30=13-4