Well that's easy, take it step by step.
123*6 =?
?/23=?
?-54=?
?+2=?
=What...?
Without a calculator here you go.
123*6=738
738/23=32
32-54=21
21+2= -19
Answer is -19 You really don't need a calculator for that, it's easy stuff to do on a piece of paper