Please help a newbie out

[vinunleaded0301]

Forgive my ignorance but I am having some issue with some of the most basic stuff on my recently purchased TI-89

When I do a simple division calculation such as 64 / 9. The answer would come out as "64/9". How do i make it display a decimal number?

[BlainUSM]

Here are two different key sequences for getting a decimal answer:

Key Sequence 1: "6", "4", "/", "9", "Green Key (with a black diamond)", "ENTER"

Key Sequence 2: "6", "4", "/", "9", ".", "ENTER"