I had a student calculate ##\tan\left(\frac{5\pi}{6}\right)## on a TI-84 calculator and he had a rounding error in the 6th or 7th decimal place. This isn't really a big deal, but he asked and we quickly found out it was because he was in fraction display mode.(adsbygoogle = window.adsbygoogle || []).push({});

I don't know too much about computational methods so I have no idea what algorithms might be by TI that would make this error occur in this situation. I am never going to ask the students for more than 4 decimal places and they know enough about rounding errors to realize that it can happens, but I am personally interested in figuring out what error makes this happen.

Thanks.

**Physics Forums | Science Articles, Homework Help, Discussion**

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# TI-84 Rounding Error in Fraction Mode

**Physics Forums | Science Articles, Homework Help, Discussion**