on 17 put parentheses on 6*11
on 18 8-3
on 19 330-150
on 20 2 *5.4
on 21 everything except answer and equal sign
on 22 4*60
on 23 everything except answer and equal sign
on 24 11*50
on 25 everything except answer and equal sign
on 26 everything except answer and equal sign