And I keep my Casio fx-4000p in my backpack for just such an occasion as I need a scientific calculator. I bought this thing sometime in the mid-80's although I may have replaced the battery once, I can't remember doing so (but I did write the battery number (cr2032) on the back sometime in the past). I've even had one of the students come scurrying in asking if anybody had a calculator they could borrow for a test (I'm a univ. research asst.) Must be the Boy Scout motto showing in my behavior ;-) Way