Calculators with Textbook Notation

If you don't have a calculator already, you may want to get one that has a display that can show conventional "textbook" notation on multiple lines. The display will look something like this:

Two good options are the TI-36X Pro (shown above) and the Casio fx-115ES PLUS. The TI-36x Pro is excellent and was recently available on Amazon for about $20. The Casio fx-115ES PLUS is also very good and was going for about $16 (the details should mention "Natural Textbook Display").