$\sin\left(\frac{\pi}{16}\right)$ not working on Ti-89

Question

If I ask TI-89 to evaluate a special angle like $\displaystyle \sin\left(\frac{\pi}{3}\right)$ or $\displaystyle \sin\left(\frac{\pi}{4}\right)$ I get back nice fractional results. But if I ask for something like $\displaystyle \sin\left(\frac{\pi}{16}\right)$ it just spits "$\displaystyle \sin\left(\frac{\pi}{16}\right)$ " back at me. Is there a way to tell it to return the decimal value?

Answer 1

I don't know for sure, but usually I believe ctrl + equals works.