bianca entered 52 + 8 x 2 = in her calculator. She got the answer 120. In what order did Bianca's calculator perform the operations? How do you know?
so you know that you have an answer come out as 120, so I think to start look at how you can get 120 from the available digits entered into the calculator.
You have: 52, 8, and 2. (52+8)*2 gives you something where as 52+(8*2) gives you something totally different.
So how did bianca's calculator actually take the values put into her calculator?