This tutorial demonstrates the installation and use of the significant figures tool for Ti84 calculators. This tool comes preinstalled on some calculators such as the Ti84 CE. Its free to download and install in any case from https://education.ti.com/en/us/downlo...
You;ll need the Ticonnect software to actually install the app and you'll have to download the "science tools" app as well. for more information, see education.ti.com/guides