Apple's Calculator simply doesn't cut it

[Orin]

Hey all,

 Does anyone know where I can get a Calculator to type on, rather  
than click on each of the buttons? I was doing a rather simple  
operation that I really could've, should've done in my head this  
morning. I didn't feel like it, and besides I wanted to give this  
calculator a test run, since I haven't used it before, and it  
disappointed me that there was no edit box to type the numbers in.

Does anyone know a freeware app that can do this, or perhaps Apple's  
Calculator can do it, I'm just not sure how to get the edit box up?

Thanks.